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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.

%I A050024 #23 May 03 2020 18:25:35
%S A050024 1,1,1,2,3,4,5,8,13,14,15,18,23,36,51,74,125,126,127,130,135,148,163,
%T A050024 186,237,362,489,624,787,1024,1513,2300,3813,3814,3815,3818,3823,3836,
%U A050024 3851,3874,3925,4050,4177,4312,4475,4712,5201
%N 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.
%H A050024 Ivan Neretin, <a href="/A050024/b050024.txt">Table of n, a(n) for n = 1..8193</a>
%p A050024 a := proc(n) option remember;
%p A050024       if n<4 then return [1, 1, 1][n] fi;
%p A050024       a(n-1) + a(2*(n-2) - Bits:-Iff(n-2, n-2)) end:
%p A050024 seq(a(n), n=1..50); _Petros Hadjicostas_, Nov 08 2019
%t A050024 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 A050024 (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 A050024 nonn
%O A050024 1,4
%A A050024 _Clark Kimberling_
%E A050024 Name edited by _Petros Hadjicostas_, Nov 08 2019