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 A144156 #8 Jun 02 2025 00:34:20 %S A144156 1,1,1,3,1,2,11,3,2,6,45,11,6,6,22,197,45,22,18,22,90,903,197,90,66, %T A144156 66,90,394,4279,903,394,270,242,270,394,1806,20793,4279,1806,1182,990, %U A144156 990,1182,1806,8558,103049,20793,8558,5418,4334,4050,4334,5418,8558 %N A144156 Eigentriangle, row sums = A006318. %C A144156 Row sums = A006318. Left border = A001003. %C A144156 Sum of n-th row terms = rightmost term of next row. %F A144156 Triangle read by rows, T(n,k) = A001003(n-k)*A006318(k-1) with A006318(-1)=1. (corrected by _R. J. Mathar_, Jul 19 2016) %e A144156 First few rows of the triangle = %e A144156 1; %e A144156 1, 1; %e A144156 3, 1, 2; %e A144156 11, 3, 2, 6; %e A144156 45, 11, 6, 6, 22; %e A144156 197, 45, 22, 18, 22, 90; %e A144156 903, 197, 90, 66, 66, 90, 394; %e A144156 4279, 903, 394, 270, 242, 270, 394, 1806; %e A144156 ... %e A144156 Row = (11, 3, 2, 6) = termwise products of (11, 3, 1, 1) and (1, 1, 2, 6) = (11*1, 3*1, 1*2, 1*6). %Y A144156 Cf. A001003, A006318. %K A144156 nonn,tabl %O A144156 0,4 %A A144156 _Gary W. Adamson_, Sep 12 2008