Triangular array read by rows. T(n,k) is the number of alternating permutations of [2n+1] having exactly 2k elements to the left of 1, n >= 0, 0 <= k <= n.

A362582

Triangular array read by rows. T(n,k) is the number of alternating permutations of [2n+1] having exactly 2k elements to the left of 1, n >= 0, 0 <= k <= n.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =5a(4) =6a(5) =5a(6) =61a(7) =75a(8) =75a(9) =61a(10) =1385a(11) =1708a(12) =1750a(13) =1708a(14) =1385a(15) =50521a(16) =62325a(17) =64050a(18) =64050a(19) =62325a(20) =50521a(21) =2702765a(22) =3334386a(23) =3427875a(24) =3438204a(25) =3427875a(26) =3334386a(27) =2702765a(28) =199360981a(29) =245951615

External references