A050490 a(n) = C(n)*(11n+1) where C(n) = Catalan numbers (A000108).

1, 12, 46, 170, 630, 2352, 8844, 33462, 127270, 486200, 1864356, 7171892, 27665596, 106977600, 414538200, 1609344270, 6258307590, 24373220520, 95050101300, 371125269900, 1450670612820, 5676173948640, 22230262964520, 87137141867100, 341824599040860, 1341897206800752

Offset

0,2

References

Albert H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 194-196.

Links

Andrew Howroyd, Table of n, a(n) for n = 0..200

Formula

From R. J. Mathar, Feb 13 2015: (Start)

5*(n+1)*a(n) + (-29*n-1)*a(n-1) + 18*(2*n-3)*a(n-2) = 0.

-(n+1)*(11*n-10)*a(n) + 2*(11*n+1)*(2*n-1)*a(n-1) = 0. (End)

G.f.: (5 - 9*x - 5*sqrt(1 - 4*x))/(x*sqrt(1 - 4*x)). - Amiram Eldar, Jul 08 2023

Mathematica

Table[CatalanNumber[n](11n+1), {n, 0, 20}] (* Harvey P. Dale, Jul 12 2018 *)

Prog

(Magma) [Catalan(n)*(11*n+1):n in [0..25] ]; // Marius A. Burtea, Jan 05 2020

Crossrefs

Column k=11 of A330965.

Cf. A017281, A027810, A000108.

Sequence in context: A249923 A340231 A100183 * A169881 A200669 A197471

Adjacent sequences: A050487 A050488 A050489 * A050491 A050492 A050493

Keyword

easy,nonn

Author

Barry E. Williams, Dec 27 1999

Extensions

Terms a(21) and beyond from Andrew Howroyd, Jan 05 2020

Status

approved