This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A301986 #6 Mar 31 2018 04:52:43 %S A301986 1,1,2,8,15,41,75,179,378,748,1591,3133,6369,12357,24225,46691,89301, %T A301986 169589,318413,596255,1103468,2036880,3725353,6786021,12281026, %U A301986 22107132,39604155,70566697,125209095,221048851,388705826,680465440,1186649341,2061086935 %N A301986 Expansion of Product_{k>=1} (1 + x^k)^(k*A000010(k)), where A000010 is the Euler totient function. %H A301986 Vaclav Kotesovec, <a href="/A301986/b301986.txt">Table of n, a(n) for n = 0..10000</a> %F A301986 a(n) ~ exp(2^(3/2) * 7^(1/4) * sqrt(Pi) * n^(3/4) / (3 * 5^(1/4))) * 7^(1/8) / (2^(7/4) * 5^(1/8) * Pi^(1/4) * n^(5/8)). %t A301986 nmax = 40; CoefficientList[Series[Product[(1+x^k)^(k*EulerPhi[k]), {k, 1, nmax}], {x, 0, nmax}], x] %t A301986 nmax = 40; CoefficientList[Series[Exp[Sum[(-1)^(j + 1)/j * Sum[k*EulerPhi[k] * x^(j*k), {k, 1, Floor[nmax/j] + 1}], {j, 1, nmax}]], {x, 0, nmax}], x] %Y A301986 Cf. A002618, A061255, A226106, A299069. %K A301986 nonn %O A301986 0,3 %A A301986 _Vaclav Kotesovec_, Mar 30 2018