A188198 Base-7 Keith numbers.

8, 13, 16, 19, 24, 32, 40, 48, 57, 114, 125, 145, 171, 228, 285, 329, 342, 589, 1969, 2833, 4938, 30318, 43153, 168516, 336774, 375008, 652933, 1068018, 2955098, 5658387, 11096232, 19623430, 26245925, 81805113, 112442958, 119572340, 130712398, 407198006, 494835656, 508871625, 564319261, 712864110

Offset: 1

Author

T. D. Noe, Mar 24 2011

Keywords

• nonn
• base

Comments

Keith numbers are described in A007629.

Examples

			48 is here because, in base 7, 48 is 66 and applying the Keith iteration to this number produces the numbers 6, 6, 12, 18, 30, 48.
		

Crossrefs

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

Programs

Mathematica

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[#,7]&]