OFFSET
1,1
COMMENTS
a(n) is the number whose binary representation is A138826(n).
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..660
FORMULA
From R. J. Mathar, Nov 09 2008: (Start)
a(n) = 2^(5*n-2) - 2^(3*n-1) + 2^(2*n-1) - 1.
G.f.: x*(5 +6*x -128*x^2 +768*x^3)/((1-x)*(1-4*x)*(1-8*x)*(1-32*x)). (End)
MAPLE
seq( 2^(5*n-2) -2^(3*n-1) +2^(2*n-1) -1, n=1..20); # G. C. Greubel, Jan 12 2020
MATHEMATICA
Table[FromDigits[Join[Table[1, {2n-1}], Table[0, {n}], Table[1, {2n-1}]], 2], {n, 15}] (* Stefan Steinerberger, Nov 11 2008 *)
PROG
(PARI) vector(20, n, 2^(5*n-2) -2^(3*n-1) +2^(2*n-1) -1) \\ G. C. Greubel, Jan 12 2020
(Magma) [2^(5*n-2) -2^(3*n-1) +2^(2*n-1) -1: n in [1..20]]; // G. C. Greubel, Jan 12 2020
(Sage) [2^(5*n-2) -2^(3*n-1) +2^(2*n-1) -1 for n in (1..20)] # G. C. Greubel, Jan 12 2020
(GAP) List([1..20], n-> 2^(5*n-2) -2^(3*n-1) +2^(2*n-1) -1); # G. C. Greubel, Jan 12 2020
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Omar E. Pol, Nov 06 2008
EXTENSIONS
More terms from R. J. Mathar and Stefan Steinerberger, Nov 11 2008
STATUS
approved