A049893 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) = a(2) = 1 and a(3) = 3.

1, 1, 3, 4, 8, 13, 27, 56, 112, 169, 367, 748, 1501, 3006, 6013, 12028, 24056, 36085, 78185, 159377, 320259, 641271, 1282923, 2566044, 5132145, 10264346, 20528721, 41057456, 82114917, 164229838, 328459677, 656919356, 1313838712

Offset

1,3

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, 1, 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 11 2019

Crossrefs

Cf. A049885.

Sequence in context: A347493 A091231 A250473 * A307043 A218381 A103002

Adjacent sequences: A049890 A049891 A049892 * A049894 A049895 A049896

Keyword

nonn

Author

Clark Kimberling

Extensions

Name edited by Petros Hadjicostas, Nov 11 2019

Status

approved