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A064099 a(n) = ceiling(log(3 + 2*n)/log(3)). 4
1, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Minimal number of weighings to detect a heavier or lighter counterfeit coin among n coins.

The relation is given via the inverse (A003462) and the comments in A029858. - R. J. Mathar, Sep 10 2015

REFERENCES

J. G. Mauldon, Strong solutions for the counterfeit coin problem. IBM Research Report RC 7476 (#31437) 9/15/78, IBM Thomas J. Watson Research Center, P. O. Box 218, Yorktown Heights, N. Y. 10598

LINKS

Harry J. Smith, Table of n, a(n) for n=0,...,1000

Gary Darby, The Counterfeit Coin

Gary Darby, Martin Gardner and The Counterfeit Coin Problem

M. Gardner, logic/weighing/balance.s on the counterfeit coin weighing.

FORMULA

a(n) = A134021(n+1). - Reinhard Zumkeller, Oct 19 2007

EXAMPLE

It would be nice to have some examples showing how the sequence is related to the coin problem! - N. J. A. Sloane, Jun 25 2002

MAPLE

A064099 := n->ceil(evalf(log(3+2*n)/log(3)));

MATHEMATICA

Table[Ceiling[Log[3, 3+2n]], {n, 0, 100}] (* Harvey P. Dale, Oct 26 2015 *)

PROG

(PARI) { for (n=0, 1000, write("b064099.txt", n, " ", ceil(log(3 + 2*n)/log(3))) ) } \\ Harry J. Smith, Sep 07 2009

CROSSREFS

Cf. A003462 ((3^n-1)/2, the inverse).

Sequence in context: A101787 A269024 A244160 * A134021 A330558 A237657

Adjacent sequences:  A064096 A064097 A064098 * A064100 A064101 A064102

KEYWORD

nice,easy,nonn

AUTHOR

Eugene McDonnell (EEMcD(AT)AOL.com), Sep 16 2001

STATUS

approved

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Last modified April 7 04:20 EDT 2020. Contains 333292 sequences. (Running on oeis4.)