A152761 - OEIS

%I #15 Dec 01 2019 07:15:28

%S 1,1,3,6,24,96,336,672,3024,9072,35280,120960,483840,1874880,10108800,

%T 20217600,107827200,398131200,1919877120,6051594240,24710676480,

%U 86487367680,339771801600,1141066967040,4122564526080,16784726999040

%N Sum of divisors of Catalan number A000108(n).

%H Amiram Eldar, <a href="/A152761/b152761.txt">Table of n, a(n) for n = 0..1667</a>

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

%F a(n) = A152762(n) + A000108(n). - _R. J. Mathar_, Jan 08 2009

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

%p 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

%t DivisorSigma[1,CatalanNumber[Range[0,30]]] (* _Harvey P. Dale_, Apr 17 2015 *)

%Y Cf. A000108, A000203.

%K easy,nonn

%O 0,3

%A _Omar E. Pol_, Dec 14 2008

%E Extended by _R. J. Mathar_ and _Emeric Deutsch_, Jan 08 2009