A005049 Minimal span of set of n elements with no 5-term arithmetic progression.

5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18, 23, 24, 26, 27, 28, 30, 32, 33, 35, 36, 37, 38, 40, 41, 42, 43, 48, 50, 51, 53, 55, 56, 57, 58, 60, 61, 62, 63, 65, 66, 67, 68, 75, 76, 77, 78, 80, 81, 82, 83, 85, 86, 87, 88, 90, 91, 92, 93, 104, 108, 112

Offset

5,1

Comments

If the first appearance of n in A003004 is A003004(k) = n, then a(n) = k-1. - Fausto A. C. Cariboni, Jun 17 2018

Links

Table of n, a(n) for n=5..67.

B. E. Brown and D. M. Gordon, On sequences without geometric progressions, Math. Comp. 65 (1996), no. 216, 1749-1754.

Sean A. Irvine, Example sets for a(5)-a(34)

Crossrefs

Cf. A005047, A005048, A005050.

Sequence in context: A325435 A288857 A201472 * A128427 A292917 A120182

Adjacent sequences: A005046 A005047 A005048 * A005050 A005051 A005052

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

More terms from David W. Wilson, May 15 1997

a(24)-a(34) from Sean A. Irvine, Mar 16 2016

a(33) corrected by Fausto A. C. Cariboni, Jun 17 2018

a(35)-a(67) from Fausto A. C. Cariboni, Jun 17 2018

Status

approved