A049950 a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), with a(1) = 1, a(2) = 2, and a(3) = 1.

1, 2, 1, 5, 11, 21, 43, 85, 174, 344, 689, 1377, 2758, 5522, 11054, 22130, 44302, 88520, 177041, 354081, 708166, 1416338, 2832686, 5665394, 11330830, 22661749, 45323668, 90647681, 181296050, 362593481, 725189726, 1450384984

Offset

1,2

Links

Table of n, a(n) for n=1..32.

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, 2, 1][n], s(n - 1) + a(-2^ceil(log[2](n - 1) - 1) + n - 1)); end proc;
seq(a(n), n = 1 .. 40); # Petros Hadjicostas, Apr 23 2020

Crossrefs

Sequence in context: A110352 A107310 A277279 * A095216 A307258 A174317

Adjacent sequences: A049947 A049948 A049949 * A049951 A049952 A049953

Keyword

nonn

Author

Clark Kimberling

Extensions

Name edited by Petros Hadjicostas, Apr 23 2020

Status

approved