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A152761 Sum of divisors of Catalan number A000108(n). 6
1, 1, 3, 6, 24, 96, 336, 672, 3024, 9072, 35280, 120960, 483840, 1874880, 10108800, 20217600, 107827200, 398131200, 1919877120, 6051594240, 24710676480, 86487367680, 339771801600, 1141066967040, 4122564526080, 16784726999040 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..25.

FORMULA

a(n) = sigma(A000108(n)) = A000203(A000108(n)).

a(n) = A152762(n) + A000108(n). [R. J. Mathar, Jan 08 2009]

MAPLE

with(numtheory): seq(sigma(binomial(2*n, n)/(n+1)), n = 0 .. 25); # Emeric Deutsch, Jan 10 2009

A000108 := proc(n) binomial(2*n, n)/(n+1) ; end: A000203 := proc(n) numtheory[sigma](n) ; end: A152761 := proc(n) A000203(A000108(n)) ; end: for n from 0 to 30 do printf("%d, ", A152761(n)) ; od: # R. J. Mathar, Jan 08 2009

MATHEMATICA

DivisorSigma[1, CatalanNumber[Range[0, 30]]] (* Harvey P. Dale, Apr 17 2015 *)

CROSSREFS

Cf. A000108, A000203.

Sequence in context: A132390 A327643 A296215 * A295761 A262349 A109155

Adjacent sequences:  A152758 A152759 A152760 * A152762 A152763 A152764

KEYWORD

easy,nonn

AUTHOR

Omar E. Pol, Dec 14 2008

EXTENSIONS

Extended by R. J. Mathar and Emeric Deutsch, Jan 08 2009

STATUS

approved

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Last modified October 20 20:18 EDT 2019. Contains 328273 sequences. (Running on oeis4.)