

A050054


a(n) = a(n1) + a(m) for n >= 4, where m = n  1  2^p and p is the unique integer such that 2^p < n  1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 4.


4



1, 2, 4, 5, 7, 8, 10, 14, 19, 20, 22, 26, 31, 38, 46, 56, 70, 71, 73, 77, 82, 89, 97, 107, 121, 140, 160, 182, 208, 239, 277, 323, 379, 380, 382, 386, 391, 398, 406, 416, 430, 449, 469, 491, 517, 548, 586, 632
(list;
graph;
refs;
listen;
history;
text;
internal format)



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, 2, 4][n], a(n  1) + a(2^ceil(1+log[2](n  1)) + n  1)):
end proc:
seq(a(n), n = 1..40); # Petros Hadjicostas, Nov 18 2019


MATHEMATICA

Fold[Append[#1, #1[[1]] + #1[[#2]]] &, {1, 2, 4}, Flatten@Table[k, {n, 5}, {k, 2^n}]] (* Ivan Neretin, Sep 08 2015 *)


CROSSREFS

Cf. similar sequences with different initial conditions listed in A050034.
Sequence in context: A108513 A029749 A018519 * A018371 A127964 A269929
Adjacent sequences: A050051 A050052 A050053 * A050055 A050056 A050057


KEYWORD

nonn


AUTHOR

Clark Kimberling


EXTENSIONS

Name edited by Petros Hadjicostas, Nov 18 2019


STATUS

approved



