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 A319191 #5 Sep 15 2018 15:48:46 %S A319191 1,1,-1,1,2,-3,-6,1,3,8,24,-6,-120,-30,-20,1,720,15,-5040,20,90,144, %T A319191 40320,-10,40,-840,-15,-90,-362880,-120,3628800,1,-504,5760,-420,45, %U A319191 -39916800,-45360,3360,40,479001600,630,-6227020800,504,210,403200,87178291200 %N A319191 Coefficient of p(y) / A056239(n)! in Product_{i >= 1} (1 + x_i), where p is power-sum symmetric functions and y is the integer partition with Heinz number n. %C A319191 A refinement of Stirling numbers of the first kind. %F A319191 If n = Product prime(x_i)^y_i is the prime factorization of n, then a(n) = (-1)^(Sum x_i * y_i - Sum y_i) (Sum x_i * y_i)! / (Product x_i^y_i * Product y_i!). %t A319191 primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]]; %t A319191 numPermsOfType[ptn_]:=Total[ptn]!/Times@@ptn/Times@@Factorial/@Length/@Split[ptn]; %t A319191 Table[(-1)^(Total[primeMS[n]]-PrimeOmega[n])*numPermsOfType[primeMS[n]],{n,100}] %Y A319191 An unsigned version is A124795. %Y A319191 Cf. A000041, A000110, A000258, A005651, A008480, A048994, A056239, A124794, A215366, A318762, A319182. %K A319191 sign %O A319191 1,5 %A A319191 _Gus Wiseman_, Sep 13 2018