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 A134390 #12 Sep 01 2024 14:05:09 %S A134390 1,4,3,8,8,5,13,14,12,7,19,21,20,16,9,26,29,29,26,20,11,34,38,39,37, %T A134390 32,24,13,43,48,50,49,45,38,28,15,53,59,62,62,59,53,44,32,17,64,71,75, %U A134390 76,74,69,61,50,36,19,76,84,89,91,90,86,79,69,56,40,21,89,98,104,107,107,104,98,89,77,62,44,23 %N A134390 Duplicate of A131416. %C A134390 Row sums = A127736: (1, 7, 21, 46, 85, 141, 217, ...). %F A134390 (A000012 * A002260 + A002260 * A000012) - A000012 as infinite lower triangular matrices; where A000012 = (1; 1,1; 1,1,1; ...) and A002260 = (1; 1,2; 1,2,3; ...). %e A134390 First few rows of the triangle: %e A134390 1; %e A134390 4, 3; %e A134390 8, 8, 5; %e A134390 13, 14, 12, 7; %e A134390 19, 21, 20, 16, 9; %e A134390 26, 29, 29, 26, 20, 11; %e A134390 ... %Y A134390 Cf. A002260, A127736. %K A134390 dead %O A134390 1,2 %A A134390 _Gary W. Adamson_, Oct 23 2007 %E A134390 a(6) corrected and more terms from _Georg Fischer_, Jun 05 2023