%I #11 May 06 2022 13:12:15

%S 1,2,2,3,5,11,21,34,45,122,243,478,933,1778,3200,5100,6878,18854,

%T 37707,75406,150789,301490,602624,1203948,2404574,4795394,9534236,

%U 18842388,36782318,69973190,125899386,200667970,270641160,741950288

%N a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 2 - 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.

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

%Y Cf. A049906 (similar, but with minus a(m/2)), A049954 (similar, but with plus a(m/2)), A049955 (similar, but with plus a(m)).

%K nonn

%O 1,2

%A _Clark Kimberling_

%E Name edited by _Petros Hadjicostas_, May 03 2020