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A050024 a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the smallest integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = a(3) = 1. 12

%I

%S 1,1,1,2,3,4,5,8,13,14,15,18,23,36,51,74,125,126,127,130,135,148,163,

%T 186,237,362,489,624,787,1024,1513,2300,3813,3814,3815,3818,3823,3836,

%U 3851,3874,3925,4050,4177,4312,4475,4712,5201

%N a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the smallest integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = a(3) = 1.

%H Ivan Neretin, <a href="/A050024/b050024.txt">Table of n, a(n) for n = 1..8193</a>

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

%p if n<4 then return [1, 1, 1][n] fi;

%p a(n-1) + a(2*(n-2) - Bits:-Iff(n-2, n-2)) end:

%p seq(a(n), n=1..50); _Petros Hadjicostas_, Nov 08 2019

%t Fold[Append[#1, #1[[-1]] + #1[[#2]]] &, {1, 1, 1}, Flatten@Table[2 k - 1, {n, 5}, {k, 2^n}]] (* _Ivan Neretin_, Sep 06 2015 *)

%o (PARI) lista(nn) = {nn = max(nn,3); my(va = vector(nn)); va[1] = 1; va[2] = 1; va[3] = 1; for(n=4, nn, va[n] = va[n-1] + va[2*n - 3 - 2*2^logint(n-2, 2)]); va;} \\ _Petros Hadjicostas_, May 03 2020

%K nonn

%O 1,4

%A _Clark Kimberling_

%E Name edited by _Petros Hadjicostas_, Nov 08 2019

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Last modified October 23 04:06 EDT 2021. Contains 348211 sequences. (Running on oeis4.)