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%I #15 Nov 19 2019 05:51:31
%S 1,2,4,5,7,8,10,14,19,20,22,26,31,38,46,56,70,71,73,77,82,89,97,107,
%T 121,140,160,182,208,239,277,323,379,380,382,386,391,398,406,416,430,
%U 449,469,491,517,548,586,632
%N a(n) = a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 4.
%H Ivan Neretin, <a href="/A050054/b050054.txt">Table of n, a(n) for n = 1..8193</a>
%p a := proc(n) option remember;
%p `if`(n < 4, [1, 2, 4][n], a(n - 1) + a(-2^ceil(-1+log[2](n - 1)) + n - 1)):
%p end proc:
%p seq(a(n), n = 1..40); # _Petros Hadjicostas_, Nov 18 2019
%t Fold[Append[#1, #1[[-1]] + #1[[#2]]] &, {1, 2, 4}, Flatten@Table[k, {n, 5}, {k, 2^n}]] (* _Ivan Neretin_, Sep 08 2015 *)
%Y Cf. similar sequences with different initial conditions listed in A050034.
%K nonn
%O 1,2
%A _Clark Kimberling_
%E Name edited by _Petros Hadjicostas_, Nov 18 2019
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