%I #10 Apr 26 2020 13:54:54
%S 1,3,3,6,10,22,42,84,165,335,668,1336,2669,5334,10656,21292,42542,
%T 85167,170332,340664,681325,1362646,2725280,5450540,10901038,21801995,
%U 43603820,87207307,174413946,348826559,697650453,1395295584
%N a(n) = a(1) + a(2) + ... + 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 and a(2) = a(3) = 3.
%o (PARI) lista(nn) = { my(va = vector(nn)); va[1] = 1; va[2] = 3; va[3] = 3; my(sa = vecsum(va)); for (n=4, nn, va[n] = sa - va[n - 1 - 2^ceil(-1 + log(n-1)/log(2))]; sa += va[n]; ); va; } \\ _Petros Hadjicostas_, Apr 26 2020
%K nonn
%O 1,2
%A _Clark Kimberling_
%E Name edited by _Petros Hadjicostas_, Apr 26 2020
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