A051733 Numbers n such that A051732(n) = n-1.

2, 3, 6, 7, 10, 15, 19, 27, 30, 31, 34, 42, 51, 54, 66, 70, 75, 82, 87, 90, 91, 99, 106, 114, 135, 147, 159, 174, 175, 187, 190, 195, 210, 211, 222, 231, 234, 246, 255, 262, 271, 274, 279, 282, 294, 307, 310, 327, 330, 331, 339, 351, 355, 379, 387, 394, 399, 411, 414

Offset: 1

Author

Marie-Christine Haton (Marie-Christine.Haton(AT)loria.fr)

Keywords

• easy
• nonn

Links

• Olivier Gérard and Vincenzo Librandi, Table of n, a(n) for n = 1..6000 (first 386 terms from Olivier Gérard).

Crossrefs

Cf. A051732. Equals A217948(n)/2.

Programs

Mathematica

(* v8 *) Select[Range[2,4000],Function[n,Sort[First[First[PermutationCycles@Join[Table[2r-1,{r,1,n}],Table[2r-2n,{r,n+1,2n}]]]]]==Range[2,2n-1]]] (* Olivier Gérard, Nov 08 2012 *)