login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A014293 n^(n+1)-n+1. 6
1, 1, 7, 79, 1021, 15621, 279931, 5764795, 134217721, 3486784393, 99999999991, 3138428376711, 106993205379061, 3937376385699277, 155568095557812211, 6568408355712890611, 295147905179352825841, 14063084452067724990993 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Solution to the classical "Monkey and Coconut Problem" for n sailors.

Also called "Sailors and Monkey Problem": a(n) is smallest number such that can apply C -> (C-1)(1-1/n) n times and at every step have an integer C = 1 mod n.

The expression for a(n) is easily derived from the observation that had an extra n-1 coconuts been added to the original pile a(n), the monkey would have been doomed to a zero coconut tip all through, the successive heaps of leftovers then collapsing to an ordinary G.P. of common ratio (1 - 1/n). For a total number of (n+1) interventions, we thus have n^(n+1) dividing a(n) + (n - 1), whence the formula. - Lekraj Beedassy, Jun 04 2002

REFERENCES

H. E. Dudeney, The Canterbury Puzzles, Prob. 114 pp. 160-161, 250, Nelson, London 1919.

M. Gardner, The 2nd Scientific American Book of Mathematical Puzzles & Diversions, p. 108, Simon & Shuster, NY 1961.

P. Halmos, Problems for Mathematicians Young and Old, MAA DC 1991.

W. L. Schaff, A Bibliography of Recreational Mathematics, Vol. 2 Chap. 1.18c, p. 24, NCTM Washington D. C., 1970.

LINKS

T. D. Noe, Table of n, a(n) for n=0..100

Anonymous, The Coconut Puzzle

J. Burkardt, The Coconut puzzle

Santo D'Agostino, “The Coconut Problem”; Updated With Solution, May 2011.

R. V. Gassel et al., Coconut Chaos

MathKnox, Puzzle of the week

J. S. Tanton, A collection of research problems

K. Uhland, Marx Brothers, Four Years Later [Broken link?]

K. Uhland, Marx Brothers, Four Years Later [Broken link?]

Eric Weisstein's World of Mathematics, Monkey and Coconut Problem

FORMULA

E.g.f.: e^x(1-x) + T/(1-T)^3, where T=T(x) is Euler's tree function (see A000169). - Len Smiley Dec 10 2001

MATHEMATICA

Table[n^(n+1)-n+1, {n, 0, 30}]  (* Harvey P. Dale, Mar 24 2011 *)

CROSSREFS

Sequence in context: A127890 A198973 A127859 * A176792 A186377 A112700

Adjacent sequences:  A014290 A014291 A014292 * A014294 A014295 A014296

KEYWORD

nonn,easy,nice

AUTHOR

Russ Cox

EXTENSIONS

Additional links supplied by Lekraj Beedassy.

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 20 18:11 EDT 2019. Contains 326154 sequences. (Running on oeis4.)