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A226458 G.f.: exp( Sum_{n>=1} A226459(n)*x^n/n ), where A226459(n) = Sum_{d|n} phi(d^d). 2
1, 1, 2, 8, 41, 547, 3193, 104733, 1159483, 29990445, 431859113, 24050995053, 272382000003, 21806033497537, 362394321610042, 15956110448082190, 592910703485329797, 46410258555248498805, 775743319456458483203, 99472768731785230089041 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..19.

FORMULA

The logarithmic derivative yields A226459.

EXAMPLE

G.f.: A(x) = 1 + x + 2*x^2 + 8*x^3 + 41*x^4 + 547*x^5 + 3193*x^6 +...

where

log(A(x)) = x + 3*x^2/2 + 19*x^3/3 + 131*x^4/4 + 2501*x^5/5 +...+ A226459(n)*x^n/n +...

PROG

(PARI) {A226459(n)=sumdiv(n, d, eulerphi(d^d))}

{a(n)=polcoeff(exp(sum(m=1, n+1, A226459(m)*x^m/m)+x*O(x^n)), n)}

for(n=0, 30, print1(a(n), ", "))

CROSSREFS

Cf. A226459, A226560.

Sequence in context: A125698 A231495 A052447 * A330870 A342152 A153537

Adjacent sequences:  A226455 A226456 A226457 * A226459 A226460 A226461

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jun 08 2013

STATUS

approved

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Last modified November 27 12:51 EST 2021. Contains 349394 sequences. (Running on oeis4.)