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 A145463 #4 Jun 02 2025 00:39:26 %S A145463 1,1,1,3,1,2,13,3,2,6,47,13,6,6,24,173,47,26,18,24,96,639,173,94,78, %T A145463 72,96,384,2357,639,346,282,312,288,384,1536,8695,2357,1278,1038,1128, %U A145463 1248,1152,1536,6144,32077,8695,4714,3834,4152,4512,4992,4608,6144,24576 %N A145463 Eigentriangle, row sums = A084509. %C A145463 Row sums = A084509: (1, 2, 6, 24, 96, 384, 1536,...). %C A145463 Right border = A084509 shifted: (1, 1, 2, 6, 24,...). %C A145463 Sum of n-th row terms = rightmost term of next row. %F A145463 Triangle read by rows, M * (A084509 * 0^(n-k)). M = an infinite lower triangular matrix with A084519: (1, 1, 3, 13, 47, 173,...) in every column; and (A084509 * 0^(n-k)) = an infinite lower triangular matrix with A084509 (1, 2, 6, 24, 96,...) shifted: (1, 1, 2, 6, 24, 96, 384,...) as the right diagonal and the rest zeros. %e A145463 First few rows of the triangle = %e A145463 1; %e A145463 1, 1; %e A145463 3, 1, 2; %e A145463 13, 3, 2, 6; %e A145463 47, 13, 6, 6, 24; %e A145463 173, 47, 26, 18, 24, 96; %e A145463 639, 173, 94, 78, 72, 96, 384; %e A145463 2357, 639, 346, 282, 312, 288, 384, 1536; %e A145463 ... %e A145463 Row 4 = (13, 3, 2, 6) = termwise products of (13, 3, 1, 1) and (1, 1, 2, 6). %Y A145463 A084509, Cf. A084519 %K A145463 eigen,nonn,tabl %O A145463 1,4 %A A145463 _Gary W. Adamson_, Oct 11 2008