%I #11 Nov 16 2019 03:23:32
%S 1,2,2,4,7,15,29,53,84,196,391,777,1532,3009,5711,10281,16383,38476,
%T 76951,153897,307772,615489,1230671,2460201,4916223,9821774,19582980,
%U 38935139,76947379,150209206,285751655,514138911,819473546
%N a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = a(3) = 2.
%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, 2, 2][n], s(n - 1) - a(-2^ceil(log[2](n - 1)) + 2*n - 3)):
%p end proc:
%p seq(a(n), n = 1..40); # _Petros Hadjicostas_, Nov 15 2019
%K nonn
%O 1,2
%A _Clark Kimberling_
%E Name edited by _Petros Hadjicostas_, Nov 15 2019
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