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A049965
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) = 1.
0
1, 3, 1, 8, 14, 35, 63, 128, 254, 635, 1205, 2382, 4743, 9480, 18953, 37908, 75814, 189535, 360115, 710757, 1416777, 2831193, 5661209, 11321848, 22643315, 45286504, 90572943, 181145858, 362291695, 724583384, 1449166761
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, 1][n], s(n - 1) + a(2^ceil(log[2](n - 1)) + 2 - n)):
end proc:
seq(a(n), n = 1..40); # Petros Hadjicostas, Nov 12 2019
CROSSREFS
Sequence in context: A287987 A067955 A182509 * A221736 A077108 A075847
KEYWORD
nonn
EXTENSIONS
Name edited by Petros Hadjicostas, Nov 12 2019
STATUS
approved