A049974 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), starting with a(1) = 1 and a(2) = a(3) = 3.

1, 3, 3, 8, 18, 34, 70, 140, 285, 563, 1128, 2256, 4517, 9044, 18104, 36244, 72558, 144977, 289956, 579912, 1159829, 2319668, 4639352, 9278740, 18557550, 37115245, 74230768, 148462101, 296925330, 593852921, 1187710369, 2375429798

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, 3, 3][n], s(n - 1) + a(-2^ceil(-1 + log[2](n - 1)) + n - 1)):
end proc:
seq(a(n), n = 1..40); # Petros Hadjicostas, Apr 25 2020

Crossrefs

Sequence in context: A370640 A328976 A059197 * A049972 A027376 A190659

Adjacent sequences: A049971 A049972 A049973 * A049975 A049976 A049977

Keyword

nonn

Author

Clark Kimberling

Extensions

Name edited by Petros Hadjicostas, Apr 25 2020

Status

approved