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 A187012 #25 Jun 24 2014 03:23:02
%S A187012 1,2,5,4,8,6,11,8,14,10,17,12,20,14,23,16,26,18,29,20,32,22,35,24,38,
%T A187012 26,41,28,44,30,47,32,50,34,53,36,56,38,59,40,62,42,65,44,68,46,71,48,
%U A187012 74,50,77,52,80,54,83,56,86,58,89,60,92,62,95,64
%N A187012 Antidiagonal sums of A103516.
%C A187012 This sequence differs from A081556 at least for n=24 (see comment about n=24 in A081556).
%H A187012 Vincenzo Librandi, <a href="/A187012/b187012.txt">Table of n, a(n) for n = 2..1000</a>
%F A187012 a(n) = sum{k=0..floor(n/2), 0^(k(n-2k))*(n-k+1)}. - _Paul Barry_, Aug 30 2013
%F A187012 G.f. : x^2*(1+2*x+3*x^2-x^4)/((1-x)^2*(1+x)^2).
%F A187012 a(n) = A080512(n) - 1 for n>2.
%t A187012 CoefficientList[Series[(1 + 2 x + 3 x^2 - x^4)/((1 - x)^2 (1 + x)^2), {x, 0, 40}], x] (* _Vincenzo Librandi_, Jun 24 2014 *)
%o A187012 (PARI) a(n) = sum(k=0, n\2, 0^(k*(n-2*k))*(n-k+1)); \\ _Michel Marcus_, Aug 30 2013
%K A187012 nonn,easy
%O A187012 2,2
%A A187012 _Michel Marcus_, Aug 30 2013