Triangle read by rows giving numbers B(n,k) arising in the enumeration of doubly rooted tree maps.

Terms

a(0) =1a(1) =8a(2) =2a(3) =72a(4) =30a(5) =3a(6) =720a(7) =380a(8) =72a(9) =4a(10) =7780a(11) =4690a(12) =1245a(13) =140a(14) =5a(15) =89040a(16) =58254a(17) =19152a(18) =3192a(19) =240a(20) =6a(21) =1064644a(22) =734496a(23) =279972a(24) =60648a(25) =7000a(26) =378a(27) =7a(28) =13173216a(29) =9416688