Coefficients in q-expansion of (9*E_2(q^3)-E_2(q))/8.

Terms

a(0) =1a(1) =3a(2) =9a(3) =-15a(4) =21a(5) =18a(6) =-45a(7) =24a(8) =45a(9) =-69a(10) =54a(11) =36a(12) =-105a(13) =42a(14) =72a(15) =-90a(16) =93a(17) =54a(18) =-207a(19) =60a(20) =126a(21) =-120a(22) =108a(23) =72a(24) =-225a(25) =93a(26) =126a(27) =-231a(28) =168a(29) =90