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A050489 C(n)*(10n+1) where C(n)=Catalan numbers (A000108). 1
1, 11, 42, 155, 574, 2142, 8052, 30459, 115830, 442442, 1696396, 6525246, 25169452, 97319900, 377096040, 1463921595, 5692584870, 22169259090, 86452604700, 337547269290, 1319388204420, 5162382341220, 20217646564440, 79246770753150, 310866899505084 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

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

LINKS

Table of n, a(n) for n=0..24.

FORMULA

-(n+1)*(10*n-9)*a(n) +2*(10*n+1)*(2*n-1)*a(n-1)=0. - R. J. Mathar, Dec 03 2014

MATHEMATICA

Table[CatalanNumber[n](10n+1), {n, 0, 30}] (* Harvey P. Dale, Jul 19 2011 *)

CROSSREFS

Cf. A017173, A027810, A000108.

Sequence in context: A213772 A062517 A027978 * A156533 A228811 A096638

Adjacent sequences:  A050486 A050487 A050488 * A050490 A050491 A050492

KEYWORD

easy,nonn

AUTHOR

Barry E. Williams, Dec 27 1999

EXTENSIONS

Corrected and extended by Harvey P. Dale, Jul 19 2011

STATUS

approved

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Last modified November 12 04:21 EST 2019. Contains 329051 sequences. (Running on oeis4.)