Triangle T(n,k) of number of labeled directed multigraphs (with loops), without isolated vertices, with n arrows and k vertices (n = 1,2,.., k = 1..2*n).

A120945

Triangle T(n,k) of number of labeled directed multigraphs (with loops), without isolated vertices, with n arrows and k vertices (n = 1,2,.., k = 1..2*n).

Terms

    a(0) =1a(1) =2a(2) =1a(3) =8a(4) =18a(5) =12a(6) =1a(7) =18a(8) =108a(9) =272a(10) =300a(11) =120a(12) =1a(13) =33a(14) =393a(15) =2102a(16) =5700a(17) =8160a(18) =5880a(19) =1680a(20) =1a(21) =54a(22) =1122a(23) =10688a(24) =53550a(25) =153132a(26) =258720a(27) =255360a(28) =136080a(29) =30240

External references