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 A179116 G.f.: A(x) = exp( Sum_{n>=1} 2*A179117(n)*x^n/n ), where A179117(n) = Sum_{d|n} phi(d^phi(d)). 1
 1, 2, 4, 10, 21, 236, 470, 29736, 60343, 199550, 476302, 4288159410, 8582063896, 3325768085554, 6660540885640, 13325577492746, 34102614679799, 5388161956623254232, 10777089239865231074, 10405445064118373530596 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS phi(n) = A000010(n) is the Euler totient function of n. LINKS EXAMPLE G.f.: A(x) = 1 + 2*x + 4*x^2 + 10*x^3 + 21*x^4 + 236*x^5 + 470*x^6 +... log(A(x)) = 2*x + 4*x^2/2 + 14*x^3/3 + 20*x^4/4 + 1002*x^5/5 + 40*x^6/6 +... PROG (PARI) {a(n)=polcoeff(exp(sum(m=1, n, sumdiv(m, d, 2*eulerphi(d^eulerphi(d)))*x^m/m)+x*O(x^n)), n)} CROSSREFS Cf. A179117, A000010 (phi). Sequence in context: A123445 A104431 A130666 * A036954 A109679 A023036 Adjacent sequences:  A179113 A179114 A179115 * A179117 A179118 A179119 KEYWORD nonn AUTHOR Paul D. Hanna, Jul 10 2010 STATUS approved

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Last modified September 17 06:52 EDT 2019. Contains 327119 sequences. (Running on oeis4.)