{"page":"<link rel=\"stylesheet\" href=\"https://lessonplanet.com/assets/packs/css/resources-572d6a42.css\" />\n<link rel=\"stylesheet\" href=\"https://lessonplanet.com/assets/packs/css/lp_boclips_stylesheets-f4d0de30.css\" media=\"all\" />\n<div data-title='Olympiad level counting: How many subsets of {1,…,2000} have a sum divisible by 5?' data-url='/boclips/videos/639f28deea52a836f01b414b' data-video-url='/boclips/videos/639f28deea52a836f01b414b' id='bo_player_modal'>\n<div class='boclips-resource-page modal-dialog panel-container'>\n<div class='react-notifications-root'></div>\n<div class='rp-header'>\n<div class='rp-type'>\n<i aria-hidden='true' class='fai fa-regular fa-circle-play'></i>\nVideo\n</div>\n<h1 class='rp-title' id='video-title'>\nOlympiad level counting: How many subsets of {1,…,2000} have a sum divisible by 5?\n</h1>\n<div class='rp-actions'>\n<div class='mr-1'>\n<a class=\"btn btn-success\" data-posthog-event=\"Signup: LP Signup Activity\" data-posthog-location=\"body_link_boclips\" data-remote=\"true\" href=\"/subscription/new\"><span><span>Get Free Access</span><span class=\"\"> for 10 Days</span><span>!</span></span></a>\n</div>\n</div>\n</div>\n<div class='rp-body'>\n<div class='rp-info'>\n<div aria-label='Hide resource details' class='rp-hide-info' role='button' tabindex='0'>&times;</div>\n<i aria-label='Expand resource details' class='rp-expand-info fai fa-solid fa-up-right-and-down-left-from-center' role='button' tabindex='0'></i>\n<i aria-label='Compress resource details' class='rp-compress-info fai fa-solid fa-down-left-and-up-right-to-center' role='button' tabindex='0'></i>\n<div class='rp-rating'>\n<span class='resource-pool'>\n<span class='pool-label'>Publisher:</span>\n<span class='pool-name'>\n<span class='text'><a data-publisher-id=\"30354888\" href=\"/search?publisher_ids%5B%5D=30354888\">3Blue1Brown</a></span>\n</span>\n</span>\n</div>\n<div class='rp-description'>\n<span class='short-description'>Timestamps0:00 - Puzzle statement and motivation4:31 - Simpler example6:51 - The generating function11:52 - Evaluation tricks17:24 - Roots of unity26:31 - Recap and final trick30:13 - Takeaways</span>\n<span class='full-description hide'>Timestamps<br/>0:00 - Puzzle statement and motivation<br/>4:31 - Simpler example<br/>6:51 - The generating function<br/>11:52 - Evaluation tricks<br/>17:24 - Roots of unity<br/>26:31 - Recap and final trick<br/>30:13 - Takeaways</span>\n</div>\n<div class='action-container flex justify-between'>\n<button aria-expanded='false' aria-label='Read more description' class='rp-full-description' type='button'>\n<i class='fai fa-solid fa-align-left'></i>\n<span id='read_more'>Read More</span>\n</button>\n<div class='rp-report'>\n</div>\n</div>\n<div aria-labelledby='resource-details-heading' class='rp-info-section'>\n<h2 class='title' id='resource-details-heading'>Resource Details</h2>\n<div class='rp-resource-details clearfix'>\n<div class='detail'>\n<dl>\n<dt>Curator Rating</dt>\n<dd><span class=\"star-rating\" aria-label=\"5.0 out of 5 stars\" role=\"img\"><i class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"></i><i class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"></i><i class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"></i><i class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"></i><i class=\"fa-solid fa-star text-action\" aria-hidden=\"true\"></i></span></dd>\n</dl>\n</div>\n<div class='detail'>\n<dl>\n<dt class=\"educator-rating-title\">Educator Rating</dt><dd><div class=\"educator-rating-details\" data-path=\"/educator_ratings/rrp_data?resourceable_id=122950&amp;resourceable_type=Boclips%3A%3AVideoMetadata\"><span class=\"not-yet-rated\">Not yet Rated</span></div></dd>\n</dl>\n</div>\n<div class='detail'>\n<dl>\n<dt>Media Length</dt>\n<dd>34:15</dd>\n</dl>\n</div>\n<div class='detail'>\n<dl>\n<dt>Grade</dt><dd title=\"Grade\">12th - Higher Ed</dd>\n</dl>\n</div>\n<div class='detail'>\n<dl>\n<dt>Subjects</dt><dd><span><a href=\"/search?grade_ids%5B%5D=258&amp;grade_ids%5B%5D=259&amp;search_tab_id=1&amp;subject_ids%5B%5D=365220\">Math</a></span></dd><dd class=\"text-muted\"><i class=\"fa-solid fa-lock mr5\"></i>1 more...</dd>\n</dl>\n</div>\n<div class='detail'>\n<dl>\n<dt>Media Type</dt><dd><span><a href=\"/search?grade_ids%5B%5D=258&amp;grade_ids%5B%5D=259&amp;search_tab_id=2&amp;type_ids%5B%5D=4543647\">Instructional Videos</a></span></dd>\n</dl>\n</div>\n<div class='detail'>\n<dl>\n<dt>Source:</dt>\n<div class='preview-source' data-animation='true' data-boundary='.rp-info' data-container='.rp-resource-details' data-html='false' data-title='3Blue1Brown is a channel about visualizing math, with content ranging from calculus to linear algebra, topology, neural networks and even how bitcoin works.' data-trigger='hover focus'>\n<span>3Blue1Brown</span>\n<i aria-hidden='true' class='fa-solid fa-circle-info channel-tooltip-icon' id='channel-tooltip'></i>\n</div>\n</dl>\n</div>\n<div class='detail'>\n<dl>\n<dt>Date</dt>\n<dd>2022</dd>\n</dl>\n</div>\n<div class='detail'>\n<dl>\n<i aria-hidden='true' class='fai fa-solid fa-language'></i>\n<dt>Language</dt><dd>English</dd>\n</dl>\n</div>\n<div class='detail'>\n<dl>\n<dt>Audiences</dt><dd><span><a href=\"/search?audience_ids%5B%5D=371079&amp;grade_ids%5B%5D=258&amp;grade_ids%5B%5D=259&amp;search_tab_id=1\">For Teacher Use</a></span></dd><dd class=\"text-muted\"><i class=\"fa-solid fa-lock mr5\"></i>2 more...</dd>\n</dl>\n</div>\n<div class='detail'>\n<dl>\n<dt>Usage Permissions</dt><dd>Fine Print: Educational Use</dd>\n</dl>\n</div>\n</div>\n</div>\n<div aria-labelledby='additional-materials-heading' class='rp-info-section'>\n<h2 class='title' id='additional-materials-heading'>Additional Materials</h2>\n<div class='additional-material'>\n<i aria-hidden='true' class='fai fa-solid fa-lock'></i>\n<a class=\"text-muted\" title=\"Video Transcript\" data-html=\"true\" 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aria-hidden='true' class='fa-solid fa-caret-up ml5'></i>\n</button>\n</div>\n</div>\n</div>\n<div aria-labelledby='additional-tags-heading' class='rp-info-section'>\n<h2 class='title' id='additional-tags-heading'>Additional Tags</h2>\n<div class='clearfix'>\n<div class='details-list keyterms' data-identifier='Boclips::VideoDecorator639f28deea52a836f01b414b' data-type='keyterms'>mathematics, three blue one brown, 3 blue 1 brown, 3b1b, 3brown1blue, 3 brown 1 blue, three brown one blue, generating function, dirichlet series, riemann hypothesis, moving forward, empty set, discrete sequence, toy problem, factored form, accounting question, discrete math, real reason, binary choices, strange turns, actual function, theta cubed, zeta cubed, subsets add, equal balance, hard problem, final trick, basic idea, zeta squared, successive powers, frequency information, squared term, sum divisible, odd coefficients</div>\n<div class='keyterms-toggle-buttons' data-identifier='Boclips::VideoDecorator639f28deea52a836f01b414b'>\n<button aria-expanded='false' class='more btn-link' type='button'>\n<span>Show More</span>\n<i aria-hidden='true' class='fa-solid fa-caret-down ml5'></i>\n</button>\n<button aria-expanded='true' class='less btn-link' style='display: none;' type='button'>\n<span>Show Less</span>\n<i aria-hidden='true' class='fa-solid fa-caret-up ml5'></i>\n</button>\n</div>\n</div>\n</div>\n<div aria-labelledby='classroom-considerations-heading' class='rp-info-section'>\n<h2 class='title' id='classroom-considerations-heading'>Classroom Considerations</h2>\n<div class='classroom-considerations'><div class='fai fa-solid fa-bell'></div>Best For: Explaining a topic</div><div class='classroom-considerations'><div class='fai fa-solid fa-bell'></div>Video is ad-free</div> \n</div>\n<div aria-labelledby='educator-ratings-heading' class='rp-info-section'>\n<h2 class='title sr-only' id='educator-ratings-heading'>Educator Ratings</h2>\n<div 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