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 A319113 #10 Feb 27 2022 12:01:58 %S A319113 1,0,1,2,0,44,0,1224,2688,25920,293760,3628800,25090560,762048000, %T A319113 3887170560,62749209600,1233908121600,22616539545600,321930878976000, %U A319113 10717413809356800,108951843667968000,1982497256570880000,50138292140310528000,1408088823809310720000,25175914255793258496000 %N A319113 Expansion of e.g.f. Product_{k>=1} (1 + x^prime(k)/prime(k)). %F A319113 E.g.f.: exp(Sum_{k>=1} ( Sum_{p|k, p prime} (-p)^(1-k/p) ) * x^k/k). %p A319113 seq(n!*coeff(series(mul((1+x^ithprime(k)/ithprime(k)),k=1..100),x=0,25),x,n),n=0..24); # _Paolo P. Lava_, Jan 09 2019 %t A319113 nmax = 24; CoefficientList[Series[Product[(1 + x^Prime[k]/Prime[k]), {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]! %t A319113 nmax = 24; CoefficientList[Series[Exp[Sum[Sum[Boole[PrimeQ[d]] (-d)^(1 - k/d), {d, Divisors[k]}] x^k/k, {k, 1, nmax}]], {x, 0, nmax}], x] Range[0, nmax]! %t A319113 a[n_] := a[n] = If[n == 0, 1, (n - 1)! Sum[Sum[Boole[PrimeQ[d]] (-d)^(1 - k/d), {d, Divisors[k]}] a[n - k]/(n - k)!, {k, 1, n}]]; Table[a[n], {n, 0, 24}] %o A319113 (PARI) my(N=40, x='x+O('x^N)); Vec(serlaplace(prod(k=1, N, 1+isprime(k)*x^k/k))) \\ _Seiichi Manyama_, Feb 27 2022 %Y A319113 Cf. A002099, A007838, A319112. %K A319113 nonn %O A319113 0,4 %A A319113 _Ilya Gutkovskiy_, Sep 10 2018