Expansion of (theta_3(z)*theta_3(21z)+theta_2(z)*theta_2(21z))^4.

Terms

a(0) =1a(1) =0a(2) =8a(3) =0a(4) =24a(5) =0a(6) =32a(7) =0a(8) =24a(9) =0a(10) =48a(11) =16a(12) =96a(13) =96a(14) =64a(15) =208a(16) =24a(17) =224a(18) =104a(19) =288a(20) =144a(21) =512a(22) =192a(23) =496a(24) =480a(25) =480a(26) =688a(27) =768a(28) =960a(29) =608