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 A107842 #15 Mar 15 2020 04:21:22 %S A107842 1,2,1,5,5,1,14,20,8,1,42,75,44,11,1,132,275,208,77,14,1,429,1001,910, %T A107842 440,119,17,1,1430,3640,3808,2244,798,170,20,1,4862,13260,15504,10659, %U A107842 4655,1309,230,23,1,16796,48450,62016,48279,24794,8602,2000,299,26,1 %N A107842 A number triangle of lattice walks. %C A107842 First column is A000108(n+1). Columns include A000344, A003518 and A000589. Row sums are A026671. Compare [1,1,1,...] DELTA [0,1,0,0,...] where DELTA is the operator defined in A084938. %C A107842 Transposed version in A109450. - _Philippe Deléham_, Jun 05 2007 %H A107842 Paul Barry, <a href="https://arxiv.org/abs/1912.11845">Chebyshev moments and Riordan involutions</a>, arXiv:1912.11845 [math.CO], 2019. %F A107842 Number triangle T(n, k) = (3k+2)*C(2n+k+1, n-k)/(n+2k+2). %F A107842 Column k has g.f.: x^k*C(x)^(3k+2) where C(x) is the g.f. of A000108. %e A107842 Triangle begins %e A107842 1; %e A107842 2, 1; %e A107842 5, 5, 1; %e A107842 14, 20, 8, 1; %e A107842 42, 75, 44, 11, 1; %e A107842 Triangle [1,1,1,1,1,...] DELTA [0,1,0,0,0,0,...] begins: %e A107842 1; %e A107842 1, 0; %e A107842 2, 1, 0; %e A107842 5, 5, 1, 0; %e A107842 14, 20, 8, 1, 0; %e A107842 42, 75, 44, 11, 1, 0; %e A107842 132, 275, 208, 77, 14, 1, 0; ... %K A107842 easy,nonn,tabl %O A107842 0,2 %A A107842 _Paul Barry_, May 24 2005