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%I #11 Nov 22 2020 12:24:57
%S 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 680,190,23,1,36,924,3003,3060,1330,276,27,1,45,1716,8008,11628,7315,
%U 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 Triangle T(n,m):=binomial(n+3*m+2,n-m).
%C Riordan Array (1/(1-x)^3,x/(1-x)).
%C Sum_{m=0..n} T(n,m) = A055990(n-1).
%F G.f.: 1/(1-x)^3/(1-y*x/(1-x)^4).
%e 1,
%e 3, 1,
%e 6, 7, 1,
%e 10, 28, 11, 1,
%e 15, 84, 66, 15, 1,
%e 21, 210, 286, 120, 19, 1,
%e 28, 462, 1001, 680, 190, 23, 1
%Y Cf. A000217 (1st column), A007318, A055990 (row sums).
%K nonn,tabl
%O 0,2
%A _Vladimir Kruchinin_, Nov 17 2020