A049930 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, a(2) = 3, and a(4) = 4.

1, 3, 4, 7, 12, 26, 50, 99, 195, 396, 790, 1579, 3155, 6305, 12596, 25168, 50287, 100672, 201342, 402683, 805363, 1610721, 3221428, 6442832, 12885615, 25771134, 51542067, 103083740, 206166691, 412331806, 824660462, 1649314633

Offset

1,2

Links

Table of n, a(n) for n=1..32.

Prog

(PARI) lista(nn) = { my(va = vector(nn)); va[1] = 1; va[2] = 3; va[3] = 4; 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

Crossrefs

Sequence in context: A124636 A231337 A373805 * A102938 A076784 A279815

Adjacent sequences: A049927 A049928 A049929 * A049931 A049932 A049933

Keyword

nonn

Author

Clark Kimberling

Extensions

Name edited by Petros Hadjicostas, Apr 26 2020

Status

approved