

A140577


Decimal expansion of Wroblewski's constant arising in nonaveraging sequences.


5




OFFSET

1,1


COMMENTS

A nonaveraging sequence contains no three terms which are in an arithmetic progression. Wroblewski (1984) showed that for infinite nonaveraging sequences Sup_{all nonaveraging sequences b(n)} Sum_{k>=1} 1/b(k) > 3.00849. [Typo corrected by Stefan Steinerberger, Aug 28 2008]


REFERENCES

S. R. Finch, "Erdos' Reciprocal Sum Constants." 2.20 in Mathematical Constants. Cambridge, England: Cambridge University Press, pp. 163166, 2003.
R. K. Guy, "Nonaveraging Sets. Nondividing Sets." C16 in Unsolved Problems in Number Theory, 2nd ed. New York: SpringerVerlag, pp. 131132, 1994.


LINKS

Table of n, a(n) for n=1..6.
Eric W. Weisstein, Nonaveraging Sequence.
J. Wroblewski, A Nonaveraging Set of Integers with a Large Sum of Reciprocals, Math. Comput. 43, 261262, 1984.
Index entries related to nonaveraging sequences


FORMULA

Decimal expansion of Sup_{all nonaveraging sequences b(n)} Sum_{k>=1} b(k).


CROSSREFS

Cf. A051013, A131741, A133234.
Sequence in context: A218538 A243163 A209490 * A068606 A106153 A166244
Adjacent sequences: A140574 A140575 A140576 * A140578 A140579 A140580


KEYWORD

cons,more,nonn


AUTHOR

Jonathan Vos Post, Jul 05 2008


STATUS

approved



