Number of ordered ways of writing n as a sum of 2 squares of nonnegative integers.

Terms

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