OFFSET
1,1
COMMENTS
Numbers whose binary representation are the members of A138721.
LINKS
Paolo Xausa, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (15,-70,120,-64).
FORMULA
G.f.: x*(40*x^2-24*x+5)/((x-1)*(2*x-1)*(4*x-1)*(8*x-1)). - Colin Barker, Nov 04 2012
a(n) = (2^n-1)*(2^(2*n)+1) = 8^n - 4^n + 2^n - 1. - Alois P. Heinz, Nov 04 2012
MAPLE
a:= n-> 8^n-4^n+2^n-1:
seq(a(n), n=1..30); # Alois P. Heinz, Nov 04 2012
MATHEMATICA
Table[8^n - 4^n + 2^n - 1, {n, 25}] (* Paolo Xausa, Aug 08 2024 *)
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Omar E. Pol, Oct 14 2008
EXTENSIONS
More terms from Colin Barker, Nov 04 2012
STATUS
approved