This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A116386 #7 Jul 14 2012 11:17:17 %S A116386 54,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53, %T A116386 53,53,53,53,53,54,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53,53, %U A116386 53,53,53,53,53,53,53,53,53,53,54,53,53,53,53,53,53,53,53,53,53,53,53 %N A116386 Number of calendar weeks in the year n (starting at n=0 for the year 2000). %C A116386 Since 365/7 = 52.14 > 52, every year has at least 53 weeks (although the first and / or the last calendar weeks might not be complete and belong to two different years). Only if a leap year begins in a Saturday (the last day of the calendar week), a year can have 54 different calendar weeks (being the first and last of only one day). Years with 54 calendar weeks are: 2000, 2028, 2056, 2084, 2124, 2152, etc. It happens 13 times in a 400 year cycle. %H A116386 <a href="/index/Ca#calendar">Index entries for sequences related to calendars</a> %e A116386 E.g. a(0)=54 because the year 2000 had 54 calendar weeks (since Jan 01 2000 was a Saturday and Dec 31 2000 was a Sunday) %Y A116386 Cf. A060512, A061251, A003786, A090651, A101312. %K A116386 nonn,easy %O A116386 0,1 %A A116386 _Sergio Pimentel_, Mar 15 2006