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A049969
a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n 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) = 2.
0
1, 3, 2, 9, 16, 40, 73, 147, 292, 730, 1386, 2739, 5454, 10901, 21795, 43591, 87180, 217950, 414104, 817314, 1629181, 3255647, 6509941, 13019226, 26038014, 52075883, 104151692, 208303351, 416606678, 833213349, 1666426691
OFFSET
1,2
MAPLE
s := proc(n) option remember; `if`(n < 1, 0, a(n) + s(n - 1)) end proc:
a := proc(n) option remember;
`if`(n < 4, [1, 3, 2][n], s(n - 1) + a(2^ceil(log[2](n - 1)) + 2 - n)):
end proc:
seq(a(n), n = 1..34); # Petros Hadjicostas, Nov 14 2019
CROSSREFS
Sequence in context: A076584 A309673 A154343 * A088634 A118791 A234840
KEYWORD
nonn
EXTENSIONS
Name edited by Petros Hadjicostas, Nov 14 2019
STATUS
approved