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%I #14 Mar 30 2012 17:27:25
%S 5,9,10,11,13,15,20,22,31,40,43,53,62,71,84,93,124,154,221,483,3044,
%T 18748,125973,232085,1705260,2091605,5616236,8067806,8849508,58944155,
%U 84572166,164487062,421825427,469435978,744740232
%N Base-5 Keith numbers.
%C Among bases b = 2 to 36, in b = 5 there is the third highest percentage of Keith numbers between b and b^3 (that is, numbers with two or three digits); only binary and ternary have more Keith numbers in that range.
%e a(2) = 9. In base 5, the number 9 is written 14, and the second order linear recurrence is then 1, 4, 5, 9, ... therefore 9 is a Keith number in base 5.
%e The number 14 is a Keith number in base 10 but not base 5, as we have: 2, 4, 6, 10, 16, ...
%t (* First run the program for A186830 to define keithSeq *) Select[Range[5, 10^6], Last[keithSeq[#, 5]] == # &]
%Y Cf. A007629, base-10 Keith numbers; A162724, binary Keith numbers.
%K nonn,base
%O 1,1
%A _Alonso del Arte_, Mar 17 2011
%E Extended by _T. D. Noe_, Mar 23 2011