A152766 Largest proper divisor of the Catalan number A000108(n).

1, 1, 7, 21, 66, 143, 715, 2431, 8398, 29393, 104006, 371450, 1337220, 3231615, 17678835, 64822395, 238819350, 883631595, 3282060210, 12233133510, 45741281820, 171529806825, 644952073662, 2430973200726, 9183676536076, 34766775458002, 131873975875180

Offset

2,3

Links

Amiram Eldar, Table of n, a(n) for n = 2..1669

Formula

a(n) = A032742(A000108(n)). - Amiram Eldar, Dec 01 2019

Mathematica

Divisors[CatalanNumber[#]][[-2]]&/@Range[2, 40] (* Harvey P. Dale, Jun 13 2011 *)

Crossrefs

Cf. A000108, A152761, A152762, A152763, A152764, A152765.

Sequence in context: A083596 A082541 A005032 * A152671 A113859 A245404

Adjacent sequences: A152763 A152764 A152765 * A152767 A152768 A152769

Keyword

nonn

Author

Omar E. Pol, Dec 15 2008

Extensions

Edited and extended by N. J. A. Sloane, Dec 19 2008

Status

approved