E.g.f.: exp(Sum_{n>=1} A000041(n-1)*x^n/n).

Terms

a(0) =1a(1) =1a(2) =2a(3) =8a(4) =44a(5) =316a(6) =2656a(7) =26632a(8) =299408a(9) =3809744a(10) =53425376a(11) =823627456a(12) =13758271552a(13) =248997717568