The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A049889 a(n) = a(1) + a(2) + ... + a(n-1) - a(m), 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) = 2. 0
 1, 1, 2, 3, 6, 10, 21, 43, 86, 130, 282, 575, 1154, 2311, 4623, 9247, 18494, 27742, 60108, 122528, 246213, 493005, 986303, 1972758, 3945560, 7891163, 15782348, 31564707, 63129418, 126258839, 252517679, 505035359, 1010070718, 1515106078, 3282729836, 6691718512, 13446566445 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS 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, 2][n], s(n - 1) - a(2^ceil(log[2](n - 1)) + 2 - n)): end proc: seq(a(n), n = 1..34); # Petros Hadjicostas, Nov 09 2019 CROSSREFS Sequence in context: A242563 A240513 A036650 * A014270 A127076 A137208 Adjacent sequences:  A049886 A049887 A049888 * A049890 A049891 A049892 KEYWORD nonn AUTHOR EXTENSIONS Name edited by and more terms from Petros Hadjicostas, Nov 09 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 8 23:37 EST 2021. Contains 349596 sequences. (Running on oeis4.)