A049951 a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) 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, 6, 16, 28, 60, 142, 398, 656, 1316, 2654, 5422, 11358, 24714, 58132, 163038, 267946, 535896, 1071814, 2143742, 4287998, 8577994, 17164692, 34376158, 68962130, 138728128, 280672440, 574221574, 1200240586, 2612191482

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 < 4, [1, 2, 1][n], s(n - 1) + a(-2^ceil(log[2](n - 1)) + 2*n - 2)); end proc;
seq(a(n), n = 1 .. 40); # Petros Hadjicostas, Apr 23 2020

Crossrefs

Sequence in context: A210654 A068797 A254639 * A025263 A097947 A101032

Adjacent sequences: A049948 A049949 A049950 * A049952 A049953 A049954

Keyword

nonn

Author

Clark Kimberling

Extensions

Name edited by Petros Hadjicostas, Apr 23 2020

Status

approved