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 A110135 #9 Dec 03 2016 12:18:17
%S A110135 1,2,1,6,2,1,20,8,2,1,70,32,10,2,1,252,136,44,12,2,1,924,592,214,56,
%T A110135 14,2,1,3432,2624,1052,304,68,16,2,1,12870,11776,5284,1632,406,80,18,
%U A110135 2,1,48620,53344,26840,9024,2332,520,92,20,2,1,184756,243392,137638,50304
%N A110135 Square array of expansions of 1/sqrt(1-4x-4*k*x^2), read by antidiagonals.
%C A110135 Column k has g.f. 1/sqrt(1-4x-4*k*x^2) and e.g.f. exp(2x)BesselI(0,2*sqrt(k)x). Columns include A000984, A006139, A084609, A098453. Row sums of triangle are A110136. Diagonal sums of triangle are A110137.
%F A110135 Square array T(n, k) = Sum_{j=0..floor(n/2)} C(n, j)*C(2(n-j), n)*k^j.
%F A110135 Number triangle T1(n, k) = Sum_{j=0..floor((n-k)/2)} C(n-k, j)*C(2(n-k-j), n-k)*k^j;
%e A110135 As a square array, rows start
%e A110135 1, 1, 1, 1, 1, ...
%e A110135 2, 2, 2, 2, 2, ...
%e A110135 6, 8, 10, 12, 14, 16, ...
%e A110135 20, 32, 44, 56, 68, 80, ...
%e A110135 70, 136, 214, 304, 406, 520, ...
%e A110135 252, 592, 1052, 1632, 2332, 3152, ...
%e A110135 As a number triangle, rows start
%e A110135 1;
%e A110135 2, 1;
%e A110135 6, 2, 1;
%e A110135 20, 8, 2, 1;
%e A110135 70, 30, 10, 2, 1;
%e A110135 252, 136, 44, 12, 2, 1;
%K A110135 easy,nonn,tabl
%O A110135 0,2
%A A110135 _Paul Barry_, Jul 13 2005