T(n,k) = Number of permutations of 1..n+2*k-1 with each element displaced by at least k.

Terms

a(0) =1a(1) =1a(2) =2a(3) =1a(4) =4a(5) =9a(6) =1a(7) =8a(8) =29a(9) =44a(10) =1a(11) =16a(12) =112a(13) =206a(14) =265a(15) =1a(16) =32a(17) =436a(18) =1168a(19) =1708a(20) =1854a(21) =1a(22) =64a(23) =1708a(24) =6984a(25) =13365a(26) =15702a(27) =14833a(28) =1a(29) =128