a(n) = numerator(-1/n + Sum_{k=1..n} 2^(k-1)/k).

Terms

a(0) =0a(1) =3a(2) =3a(3) =61a(4) =25a(5) =137a(6) =343a(7) =32663a(8) =2357a(9) =74689a(10) =66671a(11) =5299069a(12) =2416531a(13) =115545821a(14) =106974277a(15) =637525199a(16) =74575583a(17) =1588674349a(18) =4496071973