Self-convolution of A023531.

Terms

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