Triangle read by rows: number of circular permutations of [1..n] with k progressions of rise 1, distance 2 and length 3 (n >= 3, k >= 0).

A216719

Triangle read by rows: number of circular permutations of [1..n] with k progressions of rise 1, distance 2 and length 3 (n >= 3, k >= 0).

Terms

    a(0) =2a(1) =6a(2) =22a(3) =2a(4) =109a(5) =10a(6) =1a(7) =657a(8) =55a(9) =7a(10) =1a(11) =4625a(12) =356a(13) =54a(14) =4a(15) =1a(16) =37186a(17) =2723a(18) =362a(19) =44a(20) =4a(21) =1a(22) =336336a(23) =23300a(24) =2837a(25) =368a(26) =34a(27) =4a(28) =1a(29) =3379058

External references