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 A143970 #4 Jun 02 2025 00:33:28 %S A143970 1,10,1,10,10,11,10,10,110,31,10,10,110,310,161,10,10,110,310,1610, %T A143970 601,10,10,110,310,1610,6010,2651,10,10,110,310,1610,6010,26510,10711 %N A143970 Eigentriangle by rows, n terms of (10 * A002535) followed by A002535(n). %C A143970 A002535 = (1, 1, 11, 31, 161, 601,...) = right border. Row sums = (1, 11, 31, 161,...) = INVERT transform of (1, 10, 10, 10,...). Sum of n-th row terms = rightmost term of next row. %F A143970 Eigentriangle by rows, n terms of (10 * A002535) followed by A002535(n) %e A143970 First few rows of the triangle = %e A143970 1; %e A143970 10, 1; %e A143970 10, 10, 11; %e A143970 10, 10, 110, 31; %e A143970 10, 10, 110, 310, 161; %e A143970 10, 10, 110, 320, 1610, 601; %e A143970 ... %Y A143970 A002535 %K A143970 nonn,tabl %O A143970 0,2 %A A143970 _Gary W. Adamson_, Sep 06 2008