%I #17 May 06 2022 13:12:16
%S 1,3,1,8,21,37,79,187,524,864,1733,3495,7140,14957,32545,76552,214699,
%T 352849,705703,1411435,2823020,5646717,11296065,22603592,45268779,
%U 90813855,182686296,369607874,756172623,1580555509,3439905037
%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, a(2) = 3, and a(3) = 1.
%o (PARI) lista(nn) = { nn = max(nn, 3); my(va = vector(nn)); va[1] = 1; va[2] = 3; va[3] = 1; 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. A049918 (similar, but with minus a(m/2)), A049919 (similar, but with minus a(m)), A049966 (similar, but with plus a(m/2)).
%K nonn
%O 1,2
%A _Clark Kimberling_
%E Name edited by _Petros Hadjicostas_, Apr 24 2020