login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A050060
a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 3 - 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) = 2.
10
1, 3, 2, 3, 5, 6, 8, 13, 21, 22, 24, 29, 37, 58, 82, 119, 201, 202, 204, 209, 217, 238, 262, 299, 381, 582, 786, 1003, 1265, 1646, 2432, 3697, 6129, 6130, 6132, 6137, 6145, 6166, 6190, 6227, 6309, 6510, 6714, 6931, 7193, 7574, 8360
OFFSET
1,2
COMMENTS
Variant of A050028 and A050044. - R. J. Mathar, Oct 15 2008
LINKS
MAPLE
a := proc(n) option remember;
`if`(n < 4, [1, 3, 2][n], a(n - 1) + a(-2^ceil(log[2](n - 1)) + 2*n - 3)):
end proc:
seq(a(n), n = 1..60); # Petros Hadjicostas, Nov 14 2019
MATHEMATICA
Fold[Append[#1, #1[[-1]] + #1[[#2]]] &, {1, 3, 2}, Flatten@Table[2 k - 1, {n, 5}, {k, 2^n}]] (* Ivan Neretin, Sep 07 2015 *)
CROSSREFS
Cf. similar sequences with different initial conditions: A050024 (1,1,1), A050028 (1,1,2), A050032 (1,1,3), A050036 (1,1,4), A050040 (1,2,1), A050044 (1,2,2), A050048 (1,2,3), A050052 (1,2,4), A050056 (1,3,1), A050064 (1,3,3), A050068 (1,3,4).
Sequence in context: A223542 A182003 A347266 * A247829 A351705 A246592
KEYWORD
nonn
EXTENSIONS
Name edited by Petros Hadjicostas, Nov 14 2019
STATUS
approved