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 A131321 #18 Dec 13 2019 09:48:11 %S A131321 1,0,1,2,0,1,0,4,0,1,5,0,6,0,1,0,14,0,8,0,1,13,0,27,0,10,0,1,0,46,0, %T A131321 44,0,12,0,1,34,0,107,0,65,0,14,0,1,0,145,0,204,0,90,0,16,0,1,89,0, %U A131321 393,0,345,0,119,0,18,0,1,0,444,0,854,0,538,0,152,0,20,0,1 %N A131321 Triangle read by rows: A168561^2. %C A131321 Left border, nonzero terms = odd indexed Fibonacci numbers: (1, 2, 5, 13, ...). Next column, nonzero terms = A030267: (1, 4, 14, 46, 145, ...). Row sums = A131322: (1, 1, 3, 5, 12, 23, 51, ...). %C A131321 Riordan array (f(x),x*f(x)) where f(x) = (1-x^2)/(1-3*x^2+x^4). Aerated version of triangle in A188137. - _Philippe Deléham_, Jan 26 2012 %F A131321 A168561 squared, as an infinite lower triangular matrix. %e A131321 First few rows of the triangle are: %e A131321 1; %e A131321 0, 1; %e A131321 2, 0, 1; %e A131321 0, 4, 0, 1; %e A131321 5, 0, 6, 0, 1; %e A131321 0, 14, 0, 8, 0, 1; %e A131321 13, 0, 27, 0, 10, 0, 1; %e A131321 ... %p A131321 F:= (n, k)-> coeff(combinat[fibonacci](n+1, x), x, k): %p A131321 T:= (n, k)-> add(F(n, j)*F(j, k), j=0..n): %p A131321 seq(seq(T(n, k), k=0..n), n=0..14); # _Alois P. Heinz_, Dec 12 2019 %Y A131321 Cf. A049310, A030267, A168561, A188137. %K A131321 nonn,tabl %O A131321 0,4 %A A131321 _Gary W. Adamson_, Jun 28 2007