A088452 The survivor w(n,4) in a modified Josephus problem, with a step of 4.

1, 1, 1, 3, 2, 6, 5, 1, 3, 10, 7, 9, 1, 2, 6, 5, 17, 18, 11, 13, 15, 10, 2, 1, 11, 10, 7, 9, 17, 30, 31, 31, 19, 22, 22, 27, 26, 23, 18, 1, 1, 1, 6, 19, 17, 18, 17, 13, 15, 14, 30, 29, 53, 50, 55, 55, 50, 33, 34, 38, 38, 39, 49, 47, 46, 46, 41, 29, 31, 1, 2, 6, 1, 1, 3, 10, 34, 34, 34, 30

Offset

1,4

Links

Table of n, a(n) for n=1..80.

Chris Groër, The Mathematics of Survival: From Antiquity to the Playground, Amer. Math. Monthly, 110(9) (2003), 812-825.

Index entries for sequences related to the Josephus Problem

Mathematica

w4[1] = v4[1] = u4[1] = 1; w4[n_] := w4[n] = Switch[ Mod[n, 4], 0, n + 1 - Ceiling[4w4[ Ceiling[3n/4]]/3], 1, n + 1 - Floor[(4w4[ Ceiling[3n/4]] + 1)/3], 2, n + 1 - Floor[4v4[ Ceiling[3n/4]]/3], 3, n + 1 - Floor[(4u4[ Ceiling[3n/4]] - 1)/3]]; v4[n_] := v4[n] = Switch[ Mod[n, 4], 0, n + 1 - Floor[(4w4[ Ceiling[3n/4]] + 1)/3], 1, n + 1 - Floor[(4v4[ Ceiling[3n/4]])/3], 2, n + 1 - Floor[(4u4[ Ceiling[3n/4]] - 1)/3], 3, n + 1 - Ceiling[ 4w4[ Floor[3n/4]]/3]]; u4[n_] := u4[n] = Switch[ Mod[n, 4], 0, n + 1 - Floor[ 4v4[ Ceiling[3n/4]]/3], 1, n + 1 - Floor[ (4u4[ Ceiling[3n/4]] - 1)/3], 2, n + 1 - Ceiling[ 4w4[ Floor[3n/4]]/3], 3, n + 1 - Floor[(4w4[ Floor[3n/4]] + 1)/3]]; Table[ w4[n], {n, 81}] (* from Chris Groer modified by Robert G. Wilson v Nov 15 2003 *)

Crossrefs

Cf. A006257, A088442, A088443, A090569.

Sequence in context: A248479 A304533 A090571 * A268719 A297878 A234922

Adjacent sequences: A088449 A088450 A088451 * A088453 A088454 A088455

Keyword

nonn

Author

N. J. A. Sloane, Nov 09 2003

Extensions

Terms computed by Chris Groer (cgroer(AT)math.uga.edu)

Status

approved