%I #11 Jan 11 2021 18:08:10
%S 3,6,16,56,216,856,3416,13656,54616,218456,873816,3495256,13981016,
%T 55924056,223696216,894784856,3579139416,14316557656,57266230616,
%U 229064922456,916259689816
%N Where 2^n appears in A340488 for the first time.
%C A subsequence of A340494 and A340497. Note that A340494 has a conjectured g.f.
%H Rémy Sigrist, <a href="/A340498/a340498.txt">C program for A340498</a>
%o (C) See Links section.
%Y Cf. A340488, A340494-A340497.
%K nonn,more
%O 0,1
%A _N. J. A. Sloane_, Jan 11 2021
%E a(8)-a(20) from _Rémy Sigrist_, Jan 11 2021