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

%I A318621 #8 Feb 16 2025 08:33:56
%S A318621 1,1,1,2,3,8,13,30,52,112,217,446,864,1750,3469,6976,13892,27828,
%T A318621 55550,111158,222224,444458,888747,1777546,3554844,7109666,14218740,
%U A318621 28437336,56874024,113747200,227493165,454985872,909968764,1819934952,3639866058,7279725522,14559441844
%N A318621 a(0) = a(1) = 1; for n > 1, a(n) = Sum_{k=0..n-2} a(k) OR a(n-k-2).
%H A318621 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%H A318621 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/OR.html">OR</a>
%F A318621 a(n) ~ c * 2^n, where c = 0.2118674483116007242958168442155...
%p A318621 a:= proc(n) option remember; `if`(n<2, 1,
%p A318621       add(Bits[Or](a(k), a(n-k-2)), k=0..n-2))
%p A318621     end:
%p A318621 seq(a(n), n=0..40); # _Alois P. Heinz_, Aug 30 2018
%t A318621 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}]
%Y A318621 Cf. A007460.
%K A318621 nonn
%O A318621 0,4
%A A318621 _Ilya Gutkovskiy_, Aug 30 2018