A140577 Decimal expansion of Wroblewski's constant arising in nonaveraging sequences.

3, 0, 0, 8, 4, 9

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

Steven R. Finch, "Erdos' Reciprocal Sum Constants." 2.20 in Mathematical Constants. Cambridge, England: Cambridge University Press, pp. 163-166, 2003.

R. K. Guy, "Nonaveraging Sets. Nondividing Sets." C16 in Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, pp. 131-132, 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, 261-262, 1984.

Index entries related to non-averaging sequences

Crossrefs

Cf. A051013, A131741, A133234.

Sequence in context: A209490 A346879 A326397 * A068606 A106153 A166244

Adjacent sequences: A140574 A140575 A140576 * A140578 A140579 A140580

Keyword

cons,more,nonn

Author

Jonathan Vos Post, Jul 05 2008

Status

approved