%I
%S 2,1,3,1,3,1,4,3,1,3,4,8,5,3,1,3,4,5,4,3,1,4,3,4,1,8,4,7,1,3,1,7,4,1,
%T 19,1,3,5,8,11,4,4,1,4,3,4,5,3,13,3,4,1,3,8,4,5,8,4,11,9,4,7,4,5,4,4,
%U 3,4,4,8,9,4,7,16,1,4,4,7,4,1,8,3,1,11,5,4,3,9,11,1,8,3,1,4,3,1,3,4,13,4,3,8
%N First differences of A067186 (A067186 gives n such that 1+t(n) is prime, where t(n) is the nth triangular number).
%C Conjecture. Except for the first term a(1)=2, this sequence does not contain terms of the form 4k+2. (This has been confirmed for the first several thousand terms.)
%Y Cf. A000217, A067186.
%K nonn
%O 1,1
%A _John W. Layman_, Oct 26 2007
