login
A087689
Numerators of successive partial sums of sum(1/(2^n-1)).
2
1, 4, 31, 54, 1709, 15536, 1982837, 33790906, 2469747943, 27183776108, 55662119048981, 241239187192714, 1976140351325516359, 28325754514689966424, 4277270178238249409079, 659561325495450888962794
OFFSET
1,2
LINKS
EXAMPLE
a(3)=31 because 1/1 + 1/3 + 1/7 = 31/21.
MAPLE
a:= n -> numer(add(1/(2^j-1), j=1..n)); // Robert Israel, Dec 28 2012
MATHEMATICA
Numerator[Accumulate[1/(2^Range[20]-1)]] (* Harvey P. Dale, Dec 28 2012 *)
CROSSREFS
Sequence in context: A371034 A216302 A070522 * A330788 A374720 A210377
KEYWORD
frac,nonn
AUTHOR
Keenan Pepper, Sep 27 2003
EXTENSIONS
More terms from Ray Chandler, Oct 26 2003
STATUS
approved