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 A082793 #7 Mar 30 2012 17:25:04 %S A082793 1,1,1,2,1,2,4,2,2,4,7,4,4,4,7,13,7,8,8,7,13,24,13,14,16,14,13,24,44, %T A082793 24,26,28,28,26,24,44 %N A082793 A tribonacci triangle in which the top two northeast and southeast diagonals consist of tribonacci numbers. %C A082793 Uses a Hosoya-like format except that the latter has the Fibonacci recursion. This triangle uses the tribonacci recursion such that every interior number can be obtained by adding the 3 previous numbers, on its diagonal. %D A082793 Thomas Koshy, <"Fibonacci and Lucas Numbers with Applications">John Wiley and Sons, 2001, Chapter 15, pages 187-195, "Hosoya's Triangle". %F A082793 T(n, j) = T(n-1, j) + T(n-2, j) + T(n-3, j); (every interior number can be obtained by adding the three previous numbers, on its diagonal.) %e A082793 T(7,3) = 14 = (8 + 4 + 2) = T(6,3) + T(5,3) + T(4,3). %Y A082793 Cf. A000073, tribonacci numbers, A058071, Hosoya's triangle. %K A082793 nonn %O A082793 1,4 %A A082793 _Gary W. Adamson_, May 24 2003