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A360651
Triangle T(n, m) = (n - m + 1)*C(2*n + 1, m)*C(2*n - m + 2, n - m + 1)/(2*n - m + 2).
0
1, 3, 3, 10, 20, 10, 35, 105, 105, 35, 126, 504, 756, 504, 126, 462, 2310, 4620, 4620, 2310, 462, 1716, 10296, 25740, 34320, 25740, 10296, 1716, 6435, 45045, 135135, 225225, 225225, 135135, 45045, 6435, 24310, 194480, 680680, 1361360, 1701700, 1361360, 680680, 194480, 24310
OFFSET
0,2
FORMULA
G.f.: 2/(1 - 4*x + sqrt(1 - 4*x - 4*x*y) - 4*x*y).
T(n, k) = binomial(n, k)*CatalanNumber(n)*(2*n + 1). - Peter Luschny, Feb 15 2023
EXAMPLE
Triangle T(n, m) starts:
[0] 1;
[1] 3, 3;
[2] 10, 20, 10;
[3] 35, 105, 105, 35;
[4] 126, 504, 756, 504, 126;
[5] 462, 2310, 4620, 4620, 2310, 462;
[6] 1716, 10296, 25740, 34320, 25740, 10296, 1716;
[7] 6435, 45045, 135135, 225225, 225225, 135135, 45045, 6435;
MAPLE
CatalanNumber := n -> binomial(2*n, n)/(n + 1):
T := (n, k) -> (2*n + 1)*CatalanNumber(n)*binomial(n, k):
seq(seq(T(n, k), k = 0..n), n = 0..8); # Peter Luschny, Feb 15 2023
PROG
(Maxima)
T(n, m):=if n<m then 0 else ((n-m+1)*binomial(2*n+1, m)*binomial(2*n-m+2, n-m+1))/(2*n-m+2);
CROSSREFS
Cf. A001700, A085880, A069720 (row sums).
Sequence in context: A077899 A049973 A025519 * A076987 A229912 A321354
KEYWORD
nonn,tabl
AUTHOR
Vladimir Kruchinin, Feb 15 2023
STATUS
approved