G.f.: Im((2*i; x)_oo), where (a; q)_oo is the q-Pochhammer symbol, i = sqrt(-1).

Terms

a(0) =-2a(1) =-2a(2) =-2a(3) =6a(4) =6a(5) =14a(6) =22a(7) =30a(8) =38a(9) =54a(10) =30a(11) =46a(12) =30a(13) =14a(14) =-34a(15) =-74a(16) =-154a(17) =-226a(18) =-362a(19) =-498a(20) =-698a(21) =-762a(22) =-1058a(23) =-1218a(24) =-1474a(25) =-1634a(26) =-1890a(27) =-1914a(28) =-2074a(29) =-2002