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 A144182 #4 Jun 02 2025 00:34:27 %S A144182 1,0,1,2,0,2,4,2,0,3,-4,4,2,0,9,0,-4,4,6,0,11,-8,0,-4,12,18,0,17,-16, %T A144182 -8,0,-12,36,22,0,35,16,-16,-8,0,-36,44,34,0,57,0,16,-16,-24,0,-44,68, %U A144182 70,0,91,32,0,16,-48,-72,0,-68,140,114,0,161 %N A144182 Eigentriangle, row sums = A144181. %C A144182 Row sums = A144181: (1, 1, 3, 9, 11, 17, 35,...). %C A144182 Left border = A118434: (1, 0, 2, 4, -4, 0, -8,...); (i.e. row sums of the self-inverse triangle A118433). %C A144182 Triangle A144183 = partial sums starting from the right of A144182. %C A144182 Sum of n-th row terms = rightmost term of next row. %F A144182 Triangle read by rows, T(n,k) = A118434(n-k)*A144181(k-1); where A144181(k-1) = A144181 shifted to (1, 1, 1, 3, 9, 11, 17, 35, 57, 91, 161,...). %e A144182 First few rows of the triangle are: %e A144182 1; %e A144182 0, 1; %e A144182 2, 0, 1; %e A144182 4, 2, 0, 3; %e A144182 -4, 4, 2, 0, 9; %e A144182 0, -4, 4, 6, 0, 11; %e A144182 -8, 0, -4, 12, 18, 0, 17; %e A144182 -16, -8, 0, -12, 36, 22, 0, 35; %e A144182 ... %e A144182 row 3 = (4, 2, 0, 3) = termwise products of (4, 2, 0, 1) and (1, 1, 1, 3) = (4*1, 2*1, 0*1, 1*3). %Y A144182 A144181, Cf. A118434, A144183 %K A144182 tabl,sign %O A144182 0,4 %A A144182 _Gary W. Adamson_, Sep 13 2008