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 A033173 #8 Jan 28 2020 00:29:27 %S A033173 365,731,1096,1461,1826,2192,2557,2922,3287,3653,4018,4383,4748,5114, %T A033173 5479,5844,6209,6575,6940,7305,7670,8036,8401,8766,9131,9497,9862, %U A033173 10227,10592,10958,11323,11688,12053,12419,12784,13149,13514,13880 %N A033173 Number of days in n years (n=2 is the first leap year). %F A033173 From _Chai Wah Wu_, Jan 27 2020: (Start) %F A033173 See caveat in A033171 formula section. %F A033173 a(n) = a(n-1) + a(n-4) - a(n-5) for n > 5. %F A033173 G.f.: x*(365*x^3 + 366*x^2 + 365*x + 365)/(x^5 - x^4 - x + 1). (End) %Y A033173 Cf. A033171. %K A033173 easy,nonn %O A033173 1,1 %A A033173 _Jeff Burch_ %E A033173 a(19) corrected by _Chai Wah Wu_, Jan 27 2020