OFFSET
1,1
COMMENTS
Equivalently, numbers such that the n-th central binomial coefficient C(2n, n) is divisible by 2n(n + 1). - Joel B. Lewis, Jan 07 2008
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10000
MATHEMATICA
fQ[n_] := fQ[n_] := IntegerQ[ Binomial[2n, n]/(2n(n + 1))]; Select[ Range@8719, fQ@# &]
Select[Range[600], Divisible[CatalanNumber[#], 2#]&] (* Harvey P. Dale, Aug 30 2016 *)
PROG
(Python)
from __future__ import division
A120624_list, b = [], 1
for n in range(1, 10**5):
if not b % (2*n):
A120624_list.append(n)
b = b*(4*n+2)//(n+2) # Chai Wah Wu, Mar 25 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jun 19 2006
EXTENSIONS
Definition corrected by Joel B. Lewis, Apr 30 2009
STATUS
approved