cp's OEIS Frontend

A226458 G.f.: exp( Sum_{n>=1} A226459(n)*x^n/n ), where A226459(n) = Sum_{d|n} phi(d^d).

%I A226458 #6 Jun 10 2013 20:55:42
%S A226458 1,1,2,8,41,547,3193,104733,1159483,29990445,431859113,24050995053,
%T A226458 272382000003,21806033497537,362394321610042,15956110448082190,
%U A226458 592910703485329797,46410258555248498805,775743319456458483203,99472768731785230089041
%N A226458 G.f.: exp( Sum_{n>=1} A226459(n)*x^n/n ), where A226459(n) = Sum_{d|n} phi(d^d).
%F A226458 The logarithmic derivative yields A226459.
%e A226458 G.f.: A(x) = 1 + x + 2*x^2 + 8*x^3 + 41*x^4 + 547*x^5 + 3193*x^6 +...
%e A226458 where
%e A226458 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 +...
%o A226458 (PARI) {A226459(n)=sumdiv(n,d, eulerphi(d^d))}
%o A226458 {a(n)=polcoeff(exp(sum(m=1, n+1, A226459(m)*x^m/m)+x*O(x^n)), n)}
%o A226458 for(n=0, 30, print1(a(n), ", "))
%Y A226458 Cf. A226459, A226560.
%K A226458 nonn
%O A226458 0,3
%A A226458 _Paul D. Hanna_, Jun 08 2013