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 A338995 #11 Nov 22 2020 12:24:57
%S A338995 1,3,1,6,7,1,10,28,11,1,15,84,66,15,1,21,210,286,120,19,1,28,462,1001,
%T A338995 680,190,23,1,36,924,3003,3060,1330,276,27,1,45,1716,8008,11628,7315,
%U A338995 2300,378,31,1,55,3003,19448,38760,33649,14950,3654,496,35,1,66,5005,43758,116280,134596,80730,27405,5456,630,39,1
%N A338995 Triangle T(n,m):=binomial(n+3*m+2,n-m).
%C A338995 Riordan Array (1/(1-x)^3,x/(1-x)).
%C A338995 Sum_{m=0..n} T(n,m) = A055990(n-1).
%F A338995 G.f.: 1/(1-x)^3/(1-y*x/(1-x)^4).
%e A338995 1,
%e A338995 3, 1,
%e A338995 6, 7, 1,
%e A338995 10, 28, 11, 1,
%e A338995 15, 84, 66, 15, 1,
%e A338995 21, 210, 286, 120, 19, 1,
%e A338995 28, 462, 1001, 680, 190, 23, 1
%Y A338995 Cf. A000217 (1st column), A007318, A055990 (row sums).
%K A338995 nonn,tabl
%O A338995 0,2
%A A338995 _Vladimir Kruchinin_, Nov 17 2020