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

0,4

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

Formula

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

Mathematica

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

Prog

(MIT Scheme:) (define (A130380 n) (floor->exact (/ (+ (A000108 n) 1) 2)))

Crossrefs

Sequence in context: A148675 A148676 A105864 * A097147 A148677 A240506

Adjacent sequences: A130377 A130378 A130379 * A130381 A130382 A130383

Keyword

nonn

Author

Antti Karttunen, Jun 11 2007

Status

approved