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 A068036 #7 Aug 27 2018 14:54:25
%S A068036 1,1,1,1,1,2,5,9,18,36,70,138,276,548,1096,2192,4374,8744,17486,34958,
%T A068036 69916,139830,279630,559260,1118520,2236988,4473964,8947920,17895736,
%U A068036 35791472,71582944,143165660,286331296,572662588,1145324764,2290649528
%N A068036 Number of subsets of {1,2,3,...,n} that sum to 0 mod 15.
%F A068036 Empirical G.f.: -(8*x^23 +4*x^21 -8*x^20 +4*x^19 -4*x^18 +2*x^17 -4*x^16 +2*x^15 -8*x^14 +2*x^12 +8*x^11 +4*x^10 +4*x^9 -6*x^8 -3*x^7 -5*x^6 -x^4 +3*x^3 +x^2 +x -1) / ((2*x-1) * (2*x^3-1) * (2*x^5-1) * (2*x^15-1)). - _Colin Barker_, Dec 22 2012
%Y A068036 15th row of A068009.
%K A068036 nonn
%O A068036 0,6
%A A068036 _Antti Karttunen_, Feb 11 2002