A050037 a(n) = 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) = a(2) = 1 and a(3) = 4.

1, 1, 4, 5, 6, 11, 15, 16, 17, 33, 48, 59, 65, 70, 74, 75, 76, 151, 225, 295, 360, 419, 467, 500, 517, 533, 548, 559, 565, 570, 574, 575, 576, 1151, 1725, 2295, 2860, 3419, 3967, 4500, 5017, 5517, 5984, 6403, 6763, 7058, 7283, 7434

Offset

1,3

Links

Ivan Neretin, Table of n, a(n) for n = 1..8193

Maple

a := proc(n) option remember;
`if`(n < 4, [1, 1, 4][n], a(n - 1) + a(2^ceil(log[2](n - 1)) + 2 - n)); end proc;
seq(a(n), n = 1 .. 48); # Petros Hadjicostas, Nov 08 2019

Mathematica

Fold[Append[#1, #1[[-1]] + #1[[#2]]] &, {1, 1, 4}, Flatten@Table[k, {n, 5}, {k, 2^n, 1, -1}]] (* Ivan Neretin, Sep 07 2015 *)

Crossrefs

Cf. similar sequences with different initial conditions: A050025 (1,1,1), A050029 (1,1,2), A050033 (1,1,3), A050041 (1,2,1), A050045 (1,2,2), A050049 (1,2,3), A050053 (1,2,4), A050057 (1,3,1), A050061 (1,3,2), A050065 (1,3,3), A050069 (1,3,4).

Sequence in context: A347269 A316783 A076138 * A113005 A301423 A072623

Adjacent sequences: A050034 A050035 A050036 * A050038 A050039 A050040

Keyword

nonn

Author

Clark Kimberling

Extensions

Name edited by Petros Hadjicostas, Nov 08 2019

Status

approved