

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
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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^n1)/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



