A118374 - OEIS

A118374

Lexicographically earliest positive integer sequence no two terms of which sum to a term of {1,7,23,63,159,...} = {n*2^n-1}, n=1,2,3,... The first differences are given in A119350.

%I #11 Apr 24 2013 06:01:29

%S 1,2,3,7,8,9,10,11,17,18,19,23,24,25,26,27,28,29,30,31,41,42,43,47,48,

%T 49,50,51,57,58,59,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,

%U 97,98,99,103,104,105,106,107,113,114,115,119,120,121,122,123,124,125

%N Lexicographically earliest positive integer sequence no two terms of which sum to a term of {1,7,23,63,159,...} = {n*2^n-1}, n=1,2,3,... The first differences are given in A119350.

%C a(1)=1 and, for n>1, a(n) is the smallest integer greater than a(n-1) such that a(n)+a(i) is not of the form k*2^k-1 for i=1,..., n-1 and for any integer k>0.

%F It appears that a(n)=a(n-1)+A119350(n).

%Y Cf. A114889, A119350.

%K nonn

%O 1,2

%A _John W. Layman_, May 15 2006