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 A127735 #13 Jun 05 2023 04:28:30 %S A127735 1,3,4,4,8,9,5,10,15,16,6,12,18,24,25,7,14,21,28,35,36,8,16,24,32,40, %T A127735 48,49,9,18,27,36,45,54,63,64,10,20,30,40,50,60,70,80,81,11,22,33,44, %U A127735 55,66,77,88,99,100,12,24,36,48,60,72,84,96,108,120,121,13,26,39,52,65,78,91,104,117,130,143,144 %N A127735 Triangle read by rows: A127701 * A002260 as infinite lower triangular matrices. %F A127735 Row sums = A127736: (1, 7, 21, 46, 85, 141, ...). %F A127735 T(n,n) = n^2. T(n,k) = k*(n+1), 1<=k<n. - _R. J. Mathar_, Jul 21 2009 %e A127735 First few rows of the triangle are: %e A127735 1; %e A127735 3, 4; %e A127735 4, 8, 9; %e A127735 5, 10, 15, 16; %e A127735 6, 12, 18, 24, 25; %e A127735 ... %Y A127735 Cf. A002260, A127701, A127736. %K A127735 nonn,tabl %O A127735 1,2 %A A127735 _Gary W. Adamson_, Jan 26 2007 %E A127735 A-number of left factor in the definition corrected by _R. J. Mathar_, Jul 21 2009 %E A127735 a(19) corrected and more terms from _Georg Fischer_, Jun 05 2023