Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #6 Mar 25 2022 00:36:02
%S 1,2,1,4,5,1,7,15,9,1,11,34,36,14,1,16,65,100,70,20,1,22,111,225,230,
%T 120,27,129,175,441,595,455,189,35,1,37,260,784,1316,1330,812,280,44,
%U 1,46,369,1296,2604,3276,2646,1344,396,54,1
%N M * A007318, M = a triangle by rows, n-th row = (n-1) zeros followed by T(n), 1.
%C Row sums = A104270: (1, 3, 10, 32, 96, 172, ...).
%C Left column = A000124.
%F M * A007318, where M = an infinite lower triangular matrix with rows: n-th row = (n-1) zeros followed by T(n), 1; T(n) = n-th triangular number. M = an infinite lower triangular matrix with (1,1,1,...) in the main diagonal and the triangular series in the subdiagonal.
%e First few rows of the triangle:
%e 1;
%e 2, 1;
%e 4, 5, 1;
%e 7, 15, 9, 1;
%e 11, 34, 36, 14, 1;
%e 16, 65, 100, 70, 20, 1;
%e ...
%Y Cf. A104270, A000124, A000217.
%K nonn,tabl
%O 0,2
%A _Gary W. Adamson_, Oct 15 2007