%I
%S 1,6,16,21,56,61,71,76,216,221,231,236,271,276,286,291,856,861,871,
%T 876,911,916,926,931,1071,1076,1086,1091,1126,1131,1141,1146,3416,
%U 3421,3431,3436,3471,3476,3486,3491,3631,3636,3646,3651,3686,3691,3701,3706,4271,4276,4286
%N Index where 2*n first appears in A340488.
%C A bisection of A340494. Note that there is a conjectured g.f. for A340494.
%H N. J. A. Sloane, <a href="/A340497/b340497.txt">Table of n, a(n) for n = 0..4095</a>
%Y Cf. A340488, A340494.
%K nonn
%O 0,2
%A _N. J. A. Sloane_, Jan 11 2021
