Triangle d_k(n) read by rows: number of n-th order Feynman diagrams with k interactions, 0<=k<=n.

A214299

Triangle d_k(n) read by rows: number of n-th order Feynman diagrams with k interactions, 0<=k<=n.

Terms

    a(0) =1a(1) =2a(2) =4a(3) =24a(4) =16a(5) =80a(6) =720a(7) =288a(8) =480a(9) =3552a(10) =40320a(11) =11520a(12) =11520a(13) =28416a(14) =271104a(15) =3628800a(16) =806400a(17) =576000a(18) =852480a(19) =2711040a(20) =31342080a(21) =479001600a(22) =87091200a(23) =48384000a(24) =51148800a(25) =97597440a(26) =376104960a(27) =5087692800a(28) =87178291200

External references