Number T(n,k) of endofunctions f on [n] that are self-inverse on [k]; triangle T(n,k), n>=0, 0<=k<=n, read by rows.
A245348
Number T(n,k) of endofunctions f on [n] that are self-inverse on [k]; triangle T(n,k), n>=0, 0<=k<=n, read by rows.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =4a(4) =3a(5) =2a(6) =27a(7) =15a(8) =8a(9) =4a(10) =256a(11) =112a(12) =50a(13) =22a(14) =10a(15) =3125a(16) =1125a(17) =430a(18) =166a(19) =66a(20) =26a(21) =46656a(22) =14256a(23) =4752a(24) =1626a(25) =576a(26) =206a(27) =76a(28) =823543a(29) =218491
External references
- oeis: A245348