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A033001 Every run of digits of n in base 3 has length 2. 31
4, 8, 36, 44, 72, 76, 328, 332, 396, 400, 652, 656, 684, 692, 2952, 2960, 2988, 2992, 3568, 3572, 3600, 3608, 5868, 5876, 5904, 5908, 6160, 6164, 6228, 6232, 26572, 26576, 26640, 26644, 26896, 26900, 26928, 26936, 32112, 32120 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See A043291 for the base 2 version (which has a very simple formula), A033002 - A033014 for bases 4 through 16, A033015 - A033029 for the variants with runs of length >= 2. - M. F. Hasler, Feb 01 2014

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..250

FORMULA

a(n)=4*A043307(n). - M. F. Hasler, Feb 01 2014

MATHEMATICA

Select[Range[10000], Union[Length/@Split[IntegerDigits[#, 3]]]=={2}&] (* Vincenzo Librandi, Feb 05 2014 *)

PROG

From M. F. Hasler, Feb 01 2014 (Start)

(PARI) is_A033001(n)=!until(!n\=9, bittest(4588304, n%27)||return)

(PARI) for(n=1, 9999, is_A033001(n)&&print1(n", ")) \\ (End)

CROSSREFS

Sequence in context: A158863 A074736 A044829 * A269012 A149110 A149111

Adjacent sequences:  A032998 A032999 A033000 * A033002 A033003 A033004

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified April 29 01:04 EDT 2017. Contains 285604 sequences.