A004059 a(n) gives position of first n in A057561.

1, 2, 4, 5, 6, 8, 9, 11, 13, 14, 15, 17, 18, 20, 22, 23, 24, 26, 28, 29, 30, 32, 34, 35, 36, 38, 40, 41, 42, 43, 45, 47, 48, 50, 51, 53, 55, 56, 57, 59, 60, 61, 64

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

References

• R. L. Graham et al., On extremal density theorems for linear forms, pp. 103-109 of H. Zassenhaus, editor, Number Theory and Algebra. Academic Press, NY, 1977.
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• Steven R. Finch, Triple-Free Sets of Integers [From Steven Finch, Apr 20 2019]

Crossrefs

Cf. A057561, A094708.

Extensions

Edited by Steven Finch, Feb 25 2009

Revised by N. J. A. Sloane, Jun 13 2012

a(21) corrected and more terms from Sean A. Irvine, Nov 18 2015