A309679 - OEIS

%I #5 Aug 12 2019 22:38:25

%S 1,2,3,4,5,8,11,14,17,20,26,32,38,44,50,60,70,80,90,100,115,130,145,

%T 160,175,198,221,244,267,290,324,358,392,426,460,508,556,604,652,700,

%U 765,830,895,960,1025,1110,1195,1280,1365,1450,1561,1672,1783,1894,2005,2148,2291,2434,2577

%N G.f. A(x) satisfies: A(x) = A(x^5) / (1 - x)^2.

%F G.f.: Product_{k>=0} 1/(1 - x^(5^k))^2.

%t nmax = 58; A[_] = 1; Do[A[x_] = A[x^5]/(1 - x)^2 + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]

%t nmax = 58; CoefficientList[Series[Product[1/(1 - x^(5^k))^2, {k, 0, Floor[Log[5, nmax]] + 1}], {x, 0, nmax}], x]

%Y Cf. A005706, A171238, A309677, A309678.

%K nonn

%O 0,2

%A _Ilya Gutkovskiy_, Aug 12 2019