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 A130460 #16 Feb 20 2022 22:53:11 %S A130460 1,1,0,0,2,0,0,0,3,0,0,0,0,4,0,0,0,0,0,5,0,0,0,0,0,0,6,0,0,0,0,0,0,0, %T A130460 7,0,0,0,0,0,0,0,0,8,0,0,0,0,0,0,0,0,0,9,0,0,0,0,0,0,0,0,0,0,10,0,0,0, %U A130460 0,0,0,0,0,0,0,0,11,0 %N A130460 Infinite lower triangular matrix,(1,0,0,0,...) in the main diagonal and (1,2,3,...) in the subdiagonal. %C A130460 Given M = this sequence as an infinite lower triangular matrix and V = any sequence as a column vector, then M*V is the concatenation of the first term of V with the dot product of (1, 2, 3, ...) and V. %F A130460 A natural number operator as an infinite lower triangular matrix M. (1,0,0,0,...) in the main diagonal, (1,2,3,...) in the subdiagonal and the rest zeros. %e A130460 First few rows of the triangle: %e A130460 1; %e A130460 1, 0; %e A130460 0, 2, 0; %e A130460 0, 0, 3, 0; %e A130460 0, 0, 0, 4, 0; %e A130460 0, 0, 0, 0, 5, 0; %e A130460 ... %Y A130460 Cf. A130461, A130476, A130477, A130478. %K A130460 nonn,tabl %O A130460 1,5 %A A130460 _Gary W. Adamson_, May 28 2007 %E A130460 a(5) corrected by _Gionata Neri_, Jun 22 2016