A005050 Minimal span of set of n elements with no 6-term arithmetic progression.

6, 7, 8, 9, 11, 12, 13, 14, 16, 17, 18, 19, 21, 22, 23, 24, 25, 28, 31, 32, 34, 35, 36, 38, 39, 40, 43, 44, 45, 47, 48, 49, 50, 53, 55, 57, 58, 60, 61, 63, 64, 65, 67, 69, 70, 72, 73, 74, 75, 79, 81, 82, 84, 85, 87, 88, 90, 92, 93, 94, 95, 97, 98, 99, 100, 104

Offset: 6

Author

N. J. A. Sloane

Keywords

• nonn

Comments

If the first appearance of n in A003005 is A003005(k) = n, then a(n) = k-1. - Fausto A. C. Cariboni, Jun 17 2018

Links

• Fausto A. C. Cariboni, Table of n, a(n) for n = 6..95
• 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(6)-a(38)

Crossrefs

Cf. A005047, A005048, A005049.

Extensions

More terms from David W. Wilson, May 15 1997

a(25)-a(38) from Sean A. Irvine, Mar 17 2016

a(39)-a(71) from Fausto A. C. Cariboni, Jun 17 2018