Irregular triangle read by rows: T(n,k) is the number of arrangements of n labeled children with exactly k rounds; n >= 2, 1 <= k <= floor(n/2).

A349280

Irregular triangle read by rows: T(n,k) is the number of arrangements of n labeled children with exactly k rounds; n >= 2, 1 <= k <= floor(n/2).

Terms

    a(0) =2a(1) =3a(2) =8a(3) =12a(4) =30a(5) =60a(6) =144a(7) =330a(8) =120a(9) =840a(10) =2100a(11) =1260a(12) =5760a(13) =15344a(14) =11760a(15) =1680a(16) =45360a(17) =127008a(18) =113400a(19) =30240a(20) =403200a(21) =1176120a(22) =1169280a(23) =428400a(24) =30240a(25) =3991680a(26) =12054240a(27) =13000680a(28) =5821200a(29) =831600

External references