%I A092482
%S A092482 1,2,3,6,7,14,15,17,18,36,37,39,40,45,46,48,49,98,99,101,102,107,108,
%T A092482 110,111,125,126,128,129,134,135,137,138,276,277,279,280,285,286,288,
%U A092482 289,303,304,306,307,312,313,315,316,357,358,360,361,366,367,369,370
%N A092482 Sequence contains no 3-term arithmetic progression, starting with "illegal" 
               1,2,3.
%C A092482 a(1)=1, a(2)=2, a(3)=3; a(n) is least k such that no three terms of a(1), 
               a(2), ..., a(n-1), k form an arithmetic progression, except for the 
               first triple (1,2,3).
%H A092482 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               NonarithmeticProgressionSequence.html">Link to a section of The World 
               of Mathematics.</a>
%F A092482 For n>2, a(n+2) = 1 + 2^[log2(n)] + sum[k=1, n, (3^A007814(n)+1)/2] = 
               1 + A053644(n) + A005836(n) (conjectured and checked up to n=512).
%Y A092482 Cf. A004793, A033157.
%Y A092482 Sequence in context: A157200 A167415 A018511 this_sequence A147303 A075427 
               A066880
%Y A092482 Adjacent sequences: A092479 A092480 A092481 this_sequence A092483 A092484 
               A092485
%K A092482 nonn
%O A092482 1,2
%A A092482 Ralf Stephan, Apr 04 2004