Consider the family of directed graphs with loops. Sequence gives the triangle read by rows giving coefficients of polynomials arising from enumeration of those graphs on n arcs and loops.
A098267
Consider the family of directed graphs with loops. Sequence gives the triangle read by rows giving coefficients of polynomials arising from enumeration of those graphs on n arcs and loops.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =6a(4) =6a(5) =1a(6) =12a(7) =72a(8) =62a(9) =15a(10) =1a(11) =12a(12) =492a(13) =1322a(14) =960a(15) =260a(16) =28a(17) =1a(18) =2520a(19) =19320a(20) =32550a(21) =20202a(22) =5600a(23) =740a(24) =45a(25) =1a(26) =10080a(27) =230160a(28) =827400a(29) =1003632
External references
- oeis: A098267