A178853 "Josephus problem": n persons stand in a circle and eliminate every seventh person counting clockwise until only person a(n) is remaining.

1, 2, 3, 2, 4, 5, 5, 4, 2, 9, 5, 12, 6, 13, 5, 12, 2, 9, 16, 3, 10, 17, 1, 8, 15, 22, 2, 9, 16, 23, 30, 5, 12, 19, 26, 33, 3, 10, 17, 24, 31, 38, 2, 9, 16, 23, 30, 37, 44, 1, 8, 15, 22, 29, 36, 43, 50, 57, 5, 12, 19, 26, 33, 40, 47, 54, 61, 68, 6, 13, 20, 27, 34, 41, 48, 55, 62, 69, 76

Offset

1,2

Comments

Several other versions of this sequence are already in the OEIS. - N. J. A. Sloane, Jun 24 2010

Links

Table of n, a(n) for n=1..79.

Leonhard Euler, Observationes circa novum et singulare progressionum genus. In: Novi Comment. Akadem. Petropol. Vol.20 (1775).

Eric Weisstein's World of Mathematics, Josephus Problem.

Index entries for sequences related to the Josephus Problem.

Mathematica

Needs["Combinatorica`"]
a[n_] := Last@ InversePermutation@ Josephus[n, 7]; Array[a, 79] (* Robert G. Wilson v, Jul 31 2010 *)

Crossrefs

Cf. A005427, A006257.

Sequence in context: A090321 A241255 A174625 * A344646 A120641 A008666

Adjacent sequences: A178850 A178851 A178852 * A178854 A178855 A178856

Keyword

nonn

Author

Roland Schroeder (florola(AT)gmx.de), Jun 18 2010

Extensions

a(29) onwards from Robert G. Wilson v, Jul 31 2010

Status

approved