Numerator of Bernoulli(n, 1/3).

Terms

a(0) =1a(1) =-1a(2) =-1a(3) =1a(4) =13a(5) =-5a(6) =-121a(7) =49a(8) =1093a(9) =-809a(10) =-49205a(11) =20317a(12) =61203943a(13) =-722813a(14) =-5580127a(15) =34607305a(16) =25949996501a(17) =-2145998417a(19) =167317266613