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Base-8 Keith numbers.
1

%I #5 Mar 30 2012 17:22:57

%S 8,11,15,16,22,24,32,37,40,48,56,59,92,123,200,251,257,400,457,893,

%T 2761,4040,4547,8392,9161,12833,16784,21225,29617,127126,238244,

%U 378733,526117,587524,599333,672549,745765,2176234,2347267,2593739,5285583,8113400,341785390,449415500,514971408

%N Base-8 Keith numbers.

%C Keith numbers are described in A007629.

%e 200 is here because, in base 8, 200 is 310 and applying the Keith iteration to this number produces the numbers 3, 1, 0, 4, 5, 9, 18, 32, 59, 109, 200.

%t IsKeith[n_,b_] := Module[{d, s, k}, d = IntegerDigits[n, b]; s = Total[d]; k = 1; While[AppendTo[d, s]; s = 2 s - d[[k]]; s < n, k++]; s == n]; Select[Range[3,10^5], IsKeith[#,8]&]

%Y Cf. A007629 (base 10), A162724 (base 2), A187713 (base 5), A188195-A188200.

%K nonn,base

%O 1,1

%A _T. D. Noe_, Mar 24 2011