Number of solutions to +-1^2 +- 2^2 +- 3^2 +- ... +- n^2 = n.

Terms

a(0) =1a(1) =1a(2) =0a(3) =0a(4) =1a(5) =2a(6) =0a(7) =0a(8) =2a(9) =4a(10) =0a(11) =0a(12) =19a(13) =29a(14) =0a(15) =0a(16) =127a(17) =208a(18) =0a(19) =0a(20) =1121a(21) =1917a(22) =0a(23) =0a(24) =10479a(25) =19360a(26) =0a(27) =0a(28) =113213a(29) =204121