A318621 a(0) = a(1) = 1; for n > 1, a(n) = Sum_{k=0..n-2} a(k) OR a(n-k-2).

1, 1, 1, 2, 3, 8, 13, 30, 52, 112, 217, 446, 864, 1750, 3469, 6976, 13892, 27828, 55550, 111158, 222224, 444458, 888747, 1777546, 3554844, 7109666, 14218740, 28437336, 56874024, 113747200, 227493165, 454985872, 909968764, 1819934952, 3639866058, 7279725522, 14559441844

Offset: 0

Author

Ilya Gutkovskiy, Aug 30 2018

Keywords

• nonn

Links

• N. J. A. Sloane, Transforms
• Eric Weisstein's World of Mathematics, OR

Crossrefs

Cf. A007460.

Programs

Maple

a:= proc(n) option remember; `if`(n<2, 1,
      add(Bits[Or](a(k), a(n-k-2)), k=0..n-2))
    end:
seq(a(n), n=0..40); # Alois P. Heinz, Aug 30 2018

Mathematica

a[0] = a[1] = 1; a[n_] := a[n] = Sum[BitOr[a[k], a[n - k - 2]], {k, 0, n - 2}]; Table[a[n], {n, 0, 36}]

Formula

a(n) ~ c * 2^n, where c = 0.2118674483116007242958168442155...