A113683 a(n)=a(n-1)/3 if a(n-1)=0(mod 3), a(n)=4*a(n-1)+2 if a(n-1)=1(mod 3), a(n)=4*a(n-1)-2 if a(n-1)=2(mod 3).

10, 42, 14, 54, 18, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2, 6, 2

Offset: 0

Author

Edwin F. Sampang, Nov 04 2005

Keywords

• nonn

Programs

Mathematica

a[0] = 10; a[n_] := a[n] = Switch[ Mod[a[n - 1], 3], 0, a[n - 1]/3, 1, 4a[n - 1] + 2, 2, 4a[n - 1] - 2]; Table[ a[n], {n, 0, 102}] (* Robert G. Wilson v, Nov 10 2005 *)
nxt[a_]:=Module[{m=Mod[a,3]},Which[m==0,a/3,m==1,4a+2,m==2,4a-2]]; NestList[ nxt,10,110] (* or *) PadRight[{10,42,14,54,18},120,{2,6}] (* Harvey P. Dale, Feb 19 2018 *)