a(n) = Numerator(binomial(n+2, 2)*Bernoulli(n, 1)) for n >= 0 and 0 for n < 0.

Terms

a(0) =0a(1) =0a(2) =1a(3) =3a(4) =1a(5) =0a(6) =-1a(7) =0a(8) =2a(9) =0a(10) =-3a(11) =0a(12) =5a(13) =0a(14) =-691a(15) =0a(16) =140a(17) =0a(18) =-10851a(19) =0a(20) =219335a(21) =0a(22) =-1222277a(23) =0a(24) =1709026a(25) =0a(26) =-1181820455a(27) =0a(28) =538845489a(29) =0