OFFSET
1,3
FORMULA
Conjecture: -(n-2)*(n+2)*(n+1)*a(n) +8*(n+1)*(n^2-3*n+1)*a(n-1) +4*(-3*n^3+18*n^2-22*n+2)*a(n-2) -32*(n-2)*(n^2-3*n+1)*a(n-3) +16*
(2*n-7)*(n-3)*(2*n-3)*a(n-4)=0. - R. J. Mathar, Jul 21 2015
MAPLE
MATHEMATICA
Table[If[OddQ[n], CatalanNumber[n], CatalanNumber[n]-CatalanNumber[n/2]], {n, 30}] (* Harvey P. Dale, May 22 2014 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Mar 15 2011
STATUS
approved