A173538 a(n) = a(n-1) + a(n-2) - [a(n-2)/4] - [a(n-3)/2] - [a(n-4)/4].

1, 1, 2, 3, 5, 7, 10, 14, 18, 23, 28, 34, 40, 47, 53, 61, 68, 77, 85, 94, 103, 113, 123, 134, 146, 158, 171, 184, 198, 212, 227, 241, 257, 272, 289, 305, 322, 339, 357, 375, 394, 414, 434, 455, 476, 498, 520, 543, 565, 589, 612

Offset

0,3

Comments

The limiting ratio a(n+1)/a(n) at the 500th iteration is:1.0039960716583698

Links

Table of n, a(n) for n=0..50.

Formula

a(n)=a(n-1)+a(n-2)-Floor[a(n-2)/4]-Floor[a(n-3)/2]-Floor[a(n-4)/4]

Mathematica

f[-2] = 0; f[-1] = 0; f[0] = 1; f[1] = 1;
f[n_] := f[n] = f[n -
1] + f[n - 2] - Floor[f[n - 2]/4] - Floor[f[n - 3]/2] - Floor[f[n - 4]/4]
Table[f[n], {n, 0, 50}]

Crossrefs

Sequence in context: A308388 A019529 A194242 * A130053 A177277 A025488

Adjacent sequences: A173535 A173536 A173537 * A173539 A173540 A173541

Keyword

nonn

Author

Roger L. Bagula, Nov 23 2010

Status

approved