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Positions of positive integers in A131389, minus 1.
9

%I #5 Nov 29 2017 03:34:09

%S 1,2,4,5,8,10,11,13,16,17,19,21,24,25,28,29,32,33,35,37,39,41,44,46,

%T 47,49,51,53,56,57,59,61,63,65,68,69,72,73,75,77,79,81,83,85,88,90,92,

%U 94,95,97,99,101,103,105,108,109,111,113,115,117,119,121,123,125,127,129

%N Positions of positive integers in A131389, minus 1.

%C If A131389 is a permutation of the integers, as conjectured, then A131391 is the complement of A131392.

%F a(n) = -1 + position of the n-th positive integer in the sequence A131389=(0,1,2,-1,3,4,-2,-3,6,-4,5,...)

%e The 5th positive integer to occur in A131391 is 6, which occurs in position 9, so that a(5) = 9 - 1 = 8.

%Y Cf. A131388, A131389, A131390, A131392, A131393, A131394, A131395, A131396, A131397.

%K nonn

%O 1,2

%A _Clark Kimberling_, Jul 06 2007