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 A142597 #4 Mar 30 2012 17:34:27
%S A142597 1,1,1,1,8,1,1,36,36,1,1,148,288,148,1,1,596,1744,1744,596,1,1,2388,
%T A142597 9360,13952,9360,2388,1,1,9556,46992,93248,93248,46992,9556,1,1,38228,
%U A142597 226192,560960,745984,560960,226192,38228,1,1,152916,1057680,3148608
%N A142597 Triangle read by rows: t(n,k)=t(n - 1, k - 1) + 4* t(n - 1, k) + 3*t(n - 1, k - 1).
%C A142597 Row sums are: {1, 2, 10, 74, 586, 4682, 37450, 299594, 2396746, 19173962, ...}.
%e A142597 Triangle begins:
%e A142597 {1},
%e A142597 {1, 1},
%e A142597 {1, 8, 1},
%e A142597 {1, 36, 36, 1},
%e A142597 {1, 148, 288, 148, 1},
%e A142597 {1, 596, 1744, 1744, 596, 1},
%e A142597 {1, 2388, 9360, 13952, 9360, 2388, 1},
%e A142597 {1, 9556, 46992, 93248, 93248, 46992, 9556, 1},
%e A142597 {1, 38228, 226192, 560960, 745984, 560960, 226192, 38228, 1},
%e A142597 {1, 152916, 1057680, 3148608, 5227776, 5227776, 3148608, 1057680, 152916, 1}
%t A142597 A[n_, 1] := 1 A[n_, n_] := 1 A[n_, k_] := A[n - 1, k - 1] + 4* A[n - 1, k] + 3*A[n - 1, k - 1]; a = Table[A[n, k], {n, 10}, {k, n}]; Flatten[a]
%Y A142597 Cf. A142175, A142467.
%Y A142597 Cf. A008292, A119258, A060187, A142175, A142467.
%K A142597 nonn,tabl
%O A142597 1,5
%A A142597 _Roger L. Bagula_, Sep 22 2008
%E A142597 Edited by _N. J. A. Sloane_, Dec 07 2008