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 A189917 #12 Jul 14 2012 10:42:42 %S A189917 0,4,8,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68,72,76,80,84,88,92, %T A189917 96,104,108,112,116,120,124,128,132,136,140,144,148,152,156,160,164, %U A189917 168,172,176,180,184,188,192,196,204,208,212,216,220,224,228,232,236,240,244,248,252,256,260,264,268,272,276,280,284,288,292,296,304,308,312,316,320,324,328,332,336,340,344,348,352,356,360,364,368,372,376,380,384,388,392,396 %N A189917 Pattern of the 97 consecutive leap years in a 400 year cycle of the Gregorian calendar. %C A189917 For each year y divisible exactly by 400 the consecutive 97 leap years, in the 400 year cycle of the Gregorian calendar, are y+a(n), n=1,2,...,97. %C A189917 A 4000 rule (declaring the years 4000,8000,... non-leap years) is not used here. %C A189917 For the leap year rule for the Gregorian calendar see, e.g., Wikipedia. %H A189917 <a href="/index/Ca#calendar">Index entries for sequences related to calendars</a> %F A189917 Eliminate in the list 4*k, k=0,..99, the numbers 100, 200 and 300. %e A189917 1600 + a(n), n=1,...,97 are leap years, %e A189917 2000 + a(n), n=1,...,97 are leap years, etc. %Y A189917 Cf. A131921. %K A189917 nonn,easy,fini,full %O A189917 1,2 %A A189917 _Wolfdieter Lang_, May 02 2011