A130380 Catalan numbers halved and rounded to the next integer.

1, 1, 1, 3, 7, 21, 66, 215, 715, 2431, 8398, 29393, 104006, 371450, 1337220, 4847423, 17678835, 64822395, 238819350, 883631595, 3282060210, 12233133510, 45741281820, 171529806825, 644952073662, 2430973200726, 9183676536076

Offset: 0

Author

Antti Karttunen, Jun 11 2007

Keywords

• nonn

Comments

Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A130918.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Programs

Mathematica

Ceiling[CatalanNumber[Range[0,30]]/2] (* Harvey P. Dale, Feb 16 2014 *)

Formula

a(n) = ceiling(A000108(n)/2) = (A000108(n)+A036987(n))/2.