A298416 a(n) = 2*a(n-1) + 2*a(n-2) - a([n/2]), where a(0) = 1, a(1) = 1, a(2) = 1.

1, 1, 1, 3, 7, 19, 49, 133, 357, 973, 2641, 7209, 19651, 53671, 146511, 400231, 1093127, 2986359, 8157999, 22287743, 60888843, 166350531, 454471539, 1241636931, 3392197289, 9267648789, 25319638485, 69174520877, 188988172213, 516325239669, 1410626423533

Offset

0,4

Comments

a(n)/a(n-1) -> 1+sqrt(3).

Links

Clark Kimberling, Table of n, a(n) for n = 0..1000

Mathematica

a[0] = 1; a[1] = 1; a[2] = 1;
a[n_] := a[n] =+ 2 a[n - 1] + 2 a[n - 2] - a[Floor[n/2]];
Table[a[n], {n, 0, 30}]  (* A298416 *)

Crossrefs

Cf. A298338, A298417.

Sequence in context: A017926 A017927 A116903 * A151266 A147234 A171854

Adjacent sequences: A298413 A298414 A298415 * A298417 A298418 A298419

Keyword

nonn,easy

Author

Clark Kimberling, Feb 11 2018

Status

approved