a(n) = n! * [x^n] exp(Sum_{k=1..n, gcd(n,k) = 1} x^k / k).

A335088

a(n) = n! * [x^n] exp(Sum_{k=1..n, gcd(n,k) = 1} x^k / k).

Terms

    a(0) =1a(1) =1a(2) =1a(3) =4a(4) =9a(5) =96a(6) =145a(7) =4320a(8) =11025a(9) =179200a(10) =693441a(11) =36288000a(12) =62610625a(13) =5748019200a(14) =15259154625a(15) =378002200576

External references