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A049889 a(n) = a(1) + a(2) + ... + a(n-1) - a(m), where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 2. 0
1, 1, 2, 3, 6, 10, 21, 43, 86, 130, 282, 575, 1154, 2311, 4623, 9247, 18494, 27742, 60108, 122528, 246213, 493005, 986303, 1972758, 3945560, 7891163, 15782348, 31564707, 63129418, 126258839, 252517679, 505035359, 1010070718, 1515106078, 3282729836, 6691718512, 13446566445 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..37.

MAPLE

s := proc(n) option remember; `if`(n < 1, 0, a(n) + s(n - 1)) end proc:

a := proc(n) option remember;

`if`(n < 4, [1, 1, 2][n], s(n - 1) - a(2^ceil(log[2](n - 1)) + 2 - n)):

end proc:

seq(a(n), n = 1..34); # Petros Hadjicostas, Nov 09 2019

CROSSREFS

Sequence in context: A242563 A240513 A036650 * A014270 A127076 A137208

Adjacent sequences:  A049886 A049887 A049888 * A049890 A049891 A049892

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Name edited by and more terms from Petros Hadjicostas, Nov 09 2019

STATUS

approved

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Last modified December 8 23:37 EST 2021. Contains 349596 sequences. (Running on oeis4.)