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A205801 E.g.f.: exp( Sum_{n>=1} x^(n^2) / (n^2) ). 2
1, 1, 1, 1, 7, 31, 91, 211, 1681, 52417, 461161, 2427481, 10744471, 219643711, 2619643027, 18939628891, 1410692293921, 23943786881281, 263853697605841, 2237281161036337, 53316533506210471, 900164075618402911, 11265158441537890891, 112769404714319769571 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Table of n, a(n) for n=0..23.

EXAMPLE

E.g.f.: A(x) = 1 + x + x^2/2! + x^3/3! + 7*x^4/4! + 31*x^5/5! + 91*x^6/6! +...

where

log(A(x)) = x + x^4/4 + x^9/9 + x^16/16 + x^25/25 + x^36/36 +...

PROG

(PARI) {a(n)=n!*polcoeff(exp(sum(m=1, sqrtint(n+1), x^(m^2)/(m^2)+x*O(x^n))), n)}

CROSSREFS

Cf. A193374, A205800, A205802.

Sequence in context: A202254 A118934 A118935 * A193437 A199921 A192596

Adjacent sequences:  A205798 A205799 A205800 * A205802 A205803 A205804

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jan 31 2012

STATUS

approved

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Last modified May 19 21:19 EDT 2013. Contains 225436 sequences.