A049925 a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, 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) = 1 and a(2) = a(3) = 3.

1, 3, 3, 4, 10, 17, 35, 70, 142, 215, 465, 948, 1903, 3812, 7625, 15250, 30502, 45755, 99135, 202083, 406075, 813105, 1626693, 3253636, 6507345, 13014762, 26029559, 52059136, 104118279, 208236564, 416473129, 832946258, 1665892518

Offset

1,2

Links

Table of n, a(n) for n=1..33.

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, 3, 3][n], s(n - 1) - a(2^ceil(log[2](n - 1)) + 2 - n)):
end proc:
seq(a(n), n = 1..34); # Petros Hadjicostas, Nov 14 2019

Crossrefs

Sequence in context: A144626 A033707 A178043 * A362107 A364910 A291873

Adjacent sequences: A049922 A049923 A049924 * A049926 A049927 A049928

Keyword

nonn

Author

Clark Kimberling

Extensions

Name edited by Petros Hadjicostas, Nov 14 2019

Status

approved