A173514 a(n) = 2*a(n-1) + a(n-2) - [a(n-2)/2] - [a(n-4)/2] - [a(n-5)/2].

1, 1, 3, 7, 16, 36, 79, 172, 373, 806, 1742, 3762, 8123, 17538, 37864, 81745, 176480, 381003, 822545, 1775788, 3833737, 8276627, 17868350, 38575848, 83281109, 179794961, 388157989, 837991360, 1809133237, 3905724120, 8432038385

Offset

0,3

Comments

The limiting ratio a(n+1)/a(n) is:2.1588924674387395

Links

Table of n, a(n) for n=0..30.

Formula

a(n) = 2*a(n - 1) + a(n - 2) - Floor[a(n - 2)/2] - Floor[a) n - 4]/2] - Floor[a(n - 5)/2].

Mathematica

a[-3] = 0; a[-2] = 0; a[-1] = 0; a[0] = 1; a[1] = 1;
a[n_] := a[n] =
    2*a[n - 1] + a[n - 2] - Floor[a[n - 2]/2] - Floor[a[n - 4]/2] -
    Floor[a[n - 5]/2]
Table[a[n], {n, 0, 30}]

Crossrefs

Sequence in context: A065979 A106463 A238441 * A045891 A081037 A019489

Adjacent sequences: A173511 A173512 A173513 * A173515 A173516 A173517

Keyword

nonn

Author

Roger L. Bagula, Nov 23 2010

Status

approved