A092370 Triangle read by rows: T(n,k)=(1/2)*C(n+k,k)*C(n,n-k).

1, 3, 3, 6, 15, 10, 10, 45, 70, 35, 15, 105, 280, 315, 126, 21, 210, 840, 1575, 1386, 462, 28, 378, 2100, 5775, 8316, 6006, 1716, 36, 630, 4620, 17325, 36036, 42042, 25740, 6435, 45, 990, 9240, 45045, 126126, 210210, 205920, 109395, 24310, 55, 1485, 17160

Offset

1,2

Links

Table of n, a(n) for n=1..48.

Mathematica

Table[(Binomial[n+k, k]Binomial[n, n-k])/2, {n, 10}, {k, n}]//Flatten (* Harvey P. Dale, Dec 29 2021 *)

Prog

(PARI) T(n, k)=(1/2)*binomial(n+k, k)*binomial(n, n-k)

Crossrefs

First column = A000217, second column = A050534, main diagonal = A001700, second diagonal = A033876.

Cf. A063007.

Sequence in context: A145597 A143418 A336452 * A245796 A345908 A006807

Adjacent sequences: A092367 A092368 A092369 * A092371 A092372 A092373

Keyword

nonn,tabl

Author

Benoit Cloitre, Mar 20 2004

Extensions

Definition corrected by Harvey P. Dale, Dec 29 2021

Status

approved