A187443 A trisection of A001405 (central binomial coefficients): binomial(3n+1,floor((3n+1)/2)), n>=0.

1, 6, 35, 252, 1716, 12870, 92378, 705432, 5200300, 40116600, 300540195, 2333606220, 17672631900, 137846528820, 1052049481860, 8233430727600, 63205303218876, 495918532948104, 3824345300380220, 30067266499541040, 232714176627630544, 1832624140942590534, 14226520737620288370, 112186277816662845432, 873065282167813104916

Offset: 0

Author

Wolfdieter Lang, Mar 10 2011

Keywords

• nonn
• easy

Comments

For trisection of sequences see a comment and a reference under A187357.

Crossrefs

Cf. A187442: binomial(3n,floor(3n/2)), A187444: binomial(3n+2,floor((3n+2)/2))/2.

Cf. A187357, A187364, A187365.

Cf. A001405.

Programs

Mathematica

Table[Binomial[3n+1,Floor[(3n+1)/2]],{n,0,30}] (* Harvey P. Dale, Jan 13 2021 *)

Formula

a(n) = binomial(3*n+1,floor((3*n+1)/2)), n>=0.

O.g.f.: 3!*x*G2(x^2) + G1(x^2), with G2(x) and G1(x) the o.g.f.s of A187365 and A187364, respectively.

Extensions

Corrected and extended by Harvey P. Dale, Jan 13 2021