%I #6 Jan 31 2019 20:07:16
%S 1,7,31,127,499,1975,7855,31327,125119,500083,1999507,7996327
%N A151723(2^n).
%C High water marks in A151723.
%F a(n) = 6*A169781(n) -6*2^n + 1.
%Y Cf. A151723, A169781.
%K nonn
%O 0,2
%A _N. J. A. Sloane_, May 12 2010
%E a(11) from Mike Warburton, Jan 31 2019.