A049961 a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 3, where m = 2^(p+1) + 2 - n and p is the smallest number such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = 2.

1, 2, 4, 9, 17, 42, 79, 156, 311, 777, 1477, 2917, 5809, 11610, 23215, 46428, 92855, 232137, 441061, 870517, 1735233, 3467574, 6933708, 13866716, 27732966, 55465777, 110931477, 221862917, 443725809, 887451610, 1774903215

Offset

1,2

Links

Table of n, a(n) for n=1..31.

Maple

s:= proc(n) option remember; `if`(n < 1, 0, a(n) + s(n - 1)) end proc:
a := proc(n) option remember;
`if`(n < 3, [1, 2][n], s(n - 1) + a(2^ceil(log[2](n - 1)) + 2 - n)):
end proc:
seq(a(n), n = 1..40); # Petros Hadjicostas, Nov 12 2019

Crossrefs

Sequence in context: A059973 A030035 A123431 * A321736 A283315 A024425

Adjacent sequences: A049958 A049959 A049960 * A049962 A049963 A049964

Keyword

nonn

Author

Clark Kimberling

Extensions

Name edited by Petros Hadjicostas, Nov 12 2019

Status

approved