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

Author

N. J. A. Sloane

Keywords

• nonn
• more

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

• 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.

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