A050096 a(n) = floor(a(n-1)/3) if this is positive and not yet in the sequence, otherwise a(n) = 8*a(n-1).

1, 8, 2, 16, 5, 40, 13, 4, 32, 10, 3, 24, 192, 64, 21, 7, 56, 18, 6, 48, 384, 128, 42, 14, 112, 37, 12, 96, 768, 256, 85, 28, 9, 72, 576, 4608, 1536, 512, 170, 1360, 453, 151, 50, 400, 133, 44, 352, 117, 39, 312, 104, 34, 11, 88, 29, 232

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Links

• Ivan Neretin, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A050000 and references therein.

Programs

Mathematica

Rest@Nest[Append[#, If[FreeQ[#, r = Quotient[#[[-1]], 3]], r, 8 #[[-1]]]] &, {0, 1}, 55] (* Ivan Neretin, Jul 31 2016 *)

PARI

first(n)=my(v=vector(n),t); v[1]=1; for(i=2,n, t=v[i-1]\3; if(t<2, v[i]=8*v[i-1]; next); for(j=1,i-1, if(v[j]==t, v[i]=8*v[i-1]; next(2))); v[i]=t); v \\ Charles R Greathouse IV, Jul 31 2016