A265831 Expansion of Product_{k>=1} 1/(1 - (5*k-1)*x^(5*k-1)).
1, 0, 0, 0, 4, 0, 0, 0, 16, 9, 0, 0, 64, 36, 14, 0, 256, 144, 137, 19, 1024, 576, 548, 202, 4120, 2304, 2192, 1537, 16847, 9245, 8768, 6148, 68522, 37462, 35106, 24592, 280649, 153151, 141382, 98407, 1122596, 622810, 572610, 394796, 4490428, 2550289, 2320167
Offset: 0
Keywords
Links
- Vaclav Kotesovec, Table of n, a(n) for n = 0..5000
Programs
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Mathematica
nmax = 40; CoefficientList[Series[Product[1/(1 - (5*k-1)*x^(5*k-1)), {k, 1, nmax}], {x, 0, nmax}], x]
Formula
a(n) ~ c * 4^(n/4), where
c = 1.073840819469157289995715447280332198042213811468819293923... if mod(n,4) = 0
c = 0.431347264451907652131063891031332936177772975542057097666... if mod(n,4) = 1
c = 0.283892524489889292147114138438462508437169743150135175791... if mod(n,4) = 2
c = 0.139829615705558896416806329024657454417365487147024035166... if mod(n,4) = 3.