A193103 - OEIS

%I #8 Oct 05 2024 21:06:14

%S 1,14,161,1678,15524,134844,1113797,8791370,66966377,495285252,

%T 3566916109,25105766336,173194384597,1173147905334,7817490983485,

%U 51328840496684,332461481754542,2126710086580138,13448964442250078,84145658562788118

%N G.f.: exp( Sum_{n>=1} 2*sigma(n*4^n)*x^n/n ).

%e G.f.: A(x) = 1 + 14*x + 161*x^2 + 1678*x^3 + 15524*x^4 + 134844*x^5 +...

%e log(A(x)) = 14*x + 126*x^2/2 + 1016*x^3/3 + 4094*x^4/4 + 24564*x^5/5 + 131064*x^6/6 + 524272*x^7/7 +...+ 2*sigma(n*4^n)*x^n/n +...

%o (PARI) {a(n)=polcoeff(exp(sum(m=1, n, 2*sigma(m*4^m)*x^m/m)+x*O(x^n)), n)}

%Y Cf. A176310, A193102, A193104.

%K nonn

%O 0,2

%A _Paul D. Hanna_, Jul 15 2011