A298415 a(n) = a(n-1) + 2*a(n-2) + a([n/2]), where a(0) = 1, a(1) = 1, a(2) = 1.

1, 1, 1, 4, 7, 16, 34, 70, 145, 292, 598, 1198, 2428, 4858, 9784, 19570, 39283, 78568, 157426, 314854, 630304, 1260610, 2522416, 5044834, 10092094, 20184190, 40373236, 80746474, 161502730, 323005462, 646030492, 1292060986, 2584161253, 5168322508, 10336723582

Offset: 0

Author

Clark Kimberling, Feb 11 2018

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A298338.

Programs

Mathematica

a[0] = 1; a[1] = 1; a[2] = 1;
a[n_] := a[n] = a[n - 1] + 2 a[n - 2] + a[Floor[n/2]];
Table[a[n], {n, 0, 30}]  (* A298415 *)