A014231 (Product of 3 successive Catalan numbers)/2.

1, 5, 70, 1470, 38808, 1189188, 40489020, 1491345570, 58388438680, 2400295633736, 102692368441936, 4542162450316400, 206643434552856000, 9631060074695610000, 458381806260954003000, 22220282755463598704250, 1094733022441519300455000, 54717445279576990999935000

Offset

0,2

Links

Harvey P. Dale, Table of n, a(n) for n = 0..560

Formula

a(n) = A014228(n)/2.

Maple

a:= proc(n) option remember; `if`(n=0, 1,
      8*(2*n-1)*(2*n+1)*(2*n+3)*a(n-1)/((n+1)*(n+2)*(n+3)))
    end:
seq(a(n), n=0..20);  # Alois P. Heinz, Oct 20 2013

Mathematica

Times@@@Partition[CatalanNumber[Range[0, 20]], 3, 1]/2 (* Harvey P. Dale, Apr 10 2013 *)

Crossrefs

Cf. A000108.

Sequence in context: A151471 A077691 A277301 * A203528 A147629 A274256

Adjacent sequences: A014228 A014229 A014230 * A014232 A014233 A014234

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved