A000801 - OEIS

A000801

a(n) = Sum_{k = 1..n} floor(2^k / k).
(Formerly M1015 N0381)

2, 4, 6, 10, 16, 26, 44, 76, 132, 234, 420, 761, 1391, 2561, 4745, 8841, 16551, 31114, 58708, 111136, 211000, 401650, 766372, 1465422, 2807599, 5388709, 10359735, 19946715, 38459505, 74250899, 143524565, 277742293, 538043341, 1043333611, 2025040421

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

REFERENCES

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

T. D. Noe, Table of n, a(n) for n = 1..500

MAPLE

A000801 := proc(n) local k; sum(floor(2^k/k), k=1..n); end;

MATHEMATICA

Table[Sum[Floor[2^k/k], {k, n}], {n, 30}] (* T. D. Noe, Jun 20 2012 *)

CROSSREFS

Cf. A000799.

Sequence in context: A307795 A065795 A293077 * A080105 A023557 A293671

Adjacent sequences: A000798 A000799 A000800 * A000802 A000803 A000804

KEYWORD

nonn

AUTHOR

N. J. A. Sloane

STATUS

approved