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 A361949 #7 Apr 06 2023 06:33:23 %S A361949 1,10,1,28,56,1,55,462,165,1,91,2002,3003,364,1,136,6188,24310,12376, %T A361949 680,1,190,15504,125970,167960,38760,1140,1,253,33649,490314,1352078, %U A361949 817190,100947,1771,1,325,65780,1562275,7726160,9657700,3124550,230230,2600,1 %N A361949 Triangle read by rows. T(n, k) = binomial(3*n - 1, 3*k - 1). %e A361949 Table T(n, k) starts: %e A361949 [1] 1; %e A361949 [2] 10, 1; %e A361949 [3] 28, 56, 1; %e A361949 [4] 55, 462, 165, 1; %e A361949 [5] 91, 2002, 3003, 364, 1; %e A361949 [6] 136, 6188, 24310, 12376, 680, 1; %e A361949 [7] 190, 15504, 125970, 167960, 38760, 1140, 1; %e A361949 [8] 253, 33649, 490314, 1352078, 817190, 100947, 1771, 1; %e A361949 [9] 325, 65780, 1562275, 7726160, 9657700, 3124550, 230230, 2600, 1. %p A361949 T := (n, k) -> binomial(3*n - 1, 3*k - 1): %p A361949 seq(print(seq(T(n, k), k = 1..n)), n = 1..8); %Y A361949 Cf. A082365 (row sums), A228888 (subdiagonal), A060544 (column 1), A066802 (central column). %K A361949 nonn,tabl %O A361949 1,2 %A A361949 _Peter Luschny_, Mar 31 2023