Triangular array C(n, r) = number of connected r-regular graphs with n nodes, 0 <= r < n.

Terms

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