A050061 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) = 1, a(2) = 3, and a(3) = 2.

1, 3, 2, 5, 6, 11, 13, 16, 17, 33, 46, 57, 63, 68, 70, 73, 74, 147, 217, 285, 348, 405, 451, 484, 501, 517, 530, 541, 547, 552, 554, 557, 558, 1115, 1669, 2221, 2768, 3309, 3839, 4356, 4857, 5341, 5792, 6197, 6545, 6830, 7047, 7194

Offset

1,2

Links

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

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)); end proc;
seq(a(n), n = 1..50); # Petros Hadjicostas, Nov 11 2019

Mathematica

Fold[Append[#1, #1[[-1]] + #1[[#2]]] &, {1, 3, 2}, Flatten@Table[k, {n, 5}, {k, 2^n, 1, -1}]] (* Ivan Neretin, Sep 08 2015 *)

Crossrefs

Cf. similar sequences with different initial conditions: A050025 (1,1,1), A050029 (1,1,2), A050033 (1,1,3), A050037 (1,1,4), A050041 (1,2,1), A050045 (1,2,2), A050049 (1,2,3), A050053 (1,2,4), A050057 (1,3,1), A050065 (1,3,3), A050069 (1,3,4).

Sequence in context: A286111 A338209 A240574 * A058638 A201218 A139140

Adjacent sequences: A050058 A050059 A050060 * A050062 A050063 A050064

Keyword

nonn

Author

Clark Kimberling

Extensions

Name edited by Petros Hadjicostas, Nov 11 2019

Status

approved