A173599 a(n) = a(n-1) + a(n-2) - [a(n-2)/4] - [a(n-4)/2] - [a(n-6)/4].

1, 1, 2, 3, 5, 8, 11, 16, 23, 31, 43, 57, 77, 101, 133, 174, 226, 293, 378, 486, 624, 800, 1023, 1307, 1669, 2129, 2714, 3458, 4405, 5609, 7139, 9085, 11560, 14706, 18706, 23792, 30258, 38478, 48929, 62216, 79108, 100583, 127886, 162597, 206726, 262829, 334154, 424833, 540115, 686677, 873006

Offset

0,3

Comments

The limiting ratio a(n+1)/a(n) at the 500th iteration is:1.2713284253471857

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-4)/2]-Floor[a(n-6)/4]

Mathematica

f[-4] = 0; f[-3] = 0; 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 - 4]/2] - Floor[f[n - 6]/4]
Table[f[n], {n, 0, 50}]

Crossrefs

Cf. A173564.

Sequence in context: A006336 A175831 A070228 * A006304 A344650 A238591

Adjacent sequences: A173596 A173597 A173598 * A173600 A173601 A173602

Keyword

nonn

Author

Roger L. Bagula, Nov 23 2010

Status

approved