A030065 a(4n)=n, a(4n+2)=a(4n)+a(4n+4), a(2n+1)=a(2n)+a(2n+2).

0, 1, 1, 2, 1, 4, 3, 5, 2, 7, 5, 8, 3, 10, 7, 11, 4, 13, 9, 14, 5, 16, 11, 17, 6, 19, 13, 20, 7, 22, 15, 23, 8, 25, 17, 26, 9, 28, 19, 29, 10, 31, 21, 32, 11, 34, 23, 35, 12, 37, 25, 38, 13, 40, 27, 41, 14, 43, 29, 44, 15, 46, 31, 47, 16, 49, 33, 50, 17, 52, 35, 53, 18, 55, 37, 56, 19, 58

Offset

0,4

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (0,0,0,2,0,0,0,-1).

Formula

a(n)=2a(n-4)-a(n-8).

Mathematica

nxt[{a_, b_, c_, d_, e_, f_, g_, h_}]:={b, c, d, e, f, g, h, 2e-a}; NestList[nxt, {0, 1, 1, 2, 1, 4, 3, 5}, 100][[;; , 1]](* or *) LinearRecurrence[{0, 0, 0, 2, 0, 0, 0, -1}, {0, 1, 1, 2, 1, 4, 3, 5}, 100](* Harvey P. Dale, Jan 30 2026 *)

Crossrefs

Sequence in context: A141210 A244373 A107640 * A362939 A328676 A269595

Adjacent sequences: A030062 A030063 A030064 * A030066 A030067 A030068

Keyword

nonn,easy

Author

J. Carl Bellinger (carlb(AT)ctron.com)

Extensions

Shorter description and more terms from David W. Wilson.

Status

approved