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 A113770 #20 Sep 08 2022 08:45:23
%S A113770 1,10,26,42,58,74,90,106,122,138,154,170,186,202,218,234,250,266,282,
%T A113770 298,314,330,346,362,378,394,410,426,442,458,474,490,506,522,538,554,
%U A113770 570,586,602,618,634,650,666,682,698,714,730,746,762,778,794
%N A113770 Partial sums of A113311(n)^2.
%C A113770 Central coefficients of number triangle A115284.
%H A113770 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A113770 G.f.: (1+8*x+7*x^2)/(1-x)^2.
%F A113770 a(n) = 7*0^n + 2*(8*n-3).
%F A113770 a(n) = sum{k=0..n, (4-C(1, k)-2*C(0, k))^2}.
%F A113770 a(n) = A115284(2n, n).
%F A113770 a(0)=1, a(1)=10, a(2)=26, a(n) = 2*a(n-1)-a(n-2). [_Harvey P. Dale_, Aug 19 2011]
%t A113770 Accumulate[CoefficientList[Series[(1+x)^2/(1-x),{x,0,110}],x]^2] (* or *) Join[{1},LinearRecurrence[{2,-1},{10,26},110]] (* _Harvey P. Dale_, Aug 19 2011 *)
%o A113770 (PARI) Vec((1+8*x+7*x^2)/(1-x)^2 + O(x^80)) \\ _Michel Marcus_, Feb 12 2016
%o A113770 (Magma) I:=[1,10,26]; [n le 3 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..60]]; // _Vincenzo Librandi_, Feb 12 2016
%K A113770 easy,nonn
%O A113770 0,2
%A A113770 _Paul Barry_, Jan 19 2006