A005050 - OEIS

%I #35 Jun 18 2018 03:26:42

%S 6,7,8,9,11,12,13,14,16,17,18,19,21,22,23,24,25,28,31,32,34,35,36,38,

%T 39,40,43,44,45,47,48,49,50,53,55,57,58,60,61,63,64,65,67,69,70,72,73,

%U 74,75,79,81,82,84,85,87,88,90,92,93,94,95,97,98,99,100,104

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

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

%H Fausto A. C. Cariboni, <a href="/A005050/b005050.txt">Table of n, a(n) for n = 6..95</a>

%H B. E. Brown and D. M. Gordon, <a href="http://dx.doi.org/10.1090/S0025-5718-96-00765-X">On sequences without geometric progressions</a>, Math. Comp. 65 (1996), no. 216, 1749-1754.

%H Sean A. Irvine, <a href="/A005050/a005050.out.txt">Example sets for a(6)-a(38)</a>

%Y Cf. A005047, A005048, A005049.

%K nonn

%O 6,1

%A _N. J. A. Sloane_

%E More terms from _David W. Wilson_, May 15 1997

%E a(25)-a(38) from _Sean A. Irvine_, Mar 17 2016

%E a(39)-a(71) from _Fausto A. C. Cariboni_, Jun 17 2018