Irregular triangle read by rows: T(n,k) (n >= 1, 0 <= k <= [n/2]) = number of permutations of 1..n with [n/2]-k runs of consecutive pairs up and down (divided by 2).
A010030
Irregular triangle read by rows: T(n,k) (n >= 1, 0 <= k <= [n/2]) = number of permutations of 1..n with [n/2]-k runs of consecutive pairs up and down (divided by 2).
Terms
- a(0) =1a(1) =1a(2) =0a(3) =3a(4) =0a(5) =3a(6) =8a(7) =1a(8) =25a(9) =28a(10) =7a(11) =17a(12) =155a(13) =143a(14) =45a(15) =259a(16) =1005a(17) =933a(18) =323a(19) =131a(20) =2770a(21) =7488a(22) =7150a(23) =2621a(24) =3177a(25) =27978a(26) =64164a(27) =62310a(28) =23811a(29) =1281
External references
- oeis: A010030