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A049931 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), starting with a(1) = 1, a(2) = 3, and a(3) = 4. 0

%I

%S 1,3,4,5,8,18,34,55,73,198,394,775,1513,2883,5189,8270,11153,30573,

%T 61144,122275,244513,488883,977189,1952270,3899153,7776003,15460304,

%U 30554000,59644613,113465493,204152989,325394485,438859978

%N 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), starting with a(1) = 1, a(2) = 3, and a(3) = 4.

%p s := proc(n) option remember; `if`(n < 1, 0, a(n) + s(n - 1)) end proc:

%p a := proc(n) option remember;

%p `if`(n < 4, [1, 3, 4][n], s(n - 1) - a(-2^ceil(log[2](n - 1)) + 2*n - 2)):

%p end proc:

%p seq(a(n), n = 1..40); # _Petros Hadjicostas_, Apr 25 2020

%K nonn

%O 1,2

%A _Clark Kimberling_

%E Name edited by _Petros Hadjicostas_, Apr 25 2020

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Last modified May 23 04:06 EDT 2022. Contains 353959 sequences. (Running on oeis4.)