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A033023 Numbers k such that every run of digits of k in base 10 has length >=2. 17

%I

%S 11,22,33,44,55,66,77,88,99,111,222,333,444,555,666,777,888,999,1100,

%T 1111,1122,1133,1144,1155,1166,1177,1188,1199,2200,2211,2222,2233,

%U 2244,2255,2266,2277,2288,2299,3300,3311,3322,3333

%N Numbers k such that every run of digits of k in base 10 has length >=2.

%C Contains A014181 as subsequence. A115853 is a supersequence. - _M. F. Hasler_, Jun 24 2016

%H Giovanni Resta, <a href="/A033023/b033023.txt">Table of n, a(n) for n = 1..10000</a> (first 1100 terms from Vincenzo Librandi)

%H Giovanni Resta, <a href="http://www.numbersaplenty.com/set/zygodrome/">Zygodrome</a>

%t Select[Range[10000], Min[Length/@Split[IntegerDigits[#, 10]]]>1&] (* _Vincenzo Librandi_, Feb 05 2014 *)

%o (PARI) is(n)={n=digits(n);while(#n>2 && n[2]==n[1], n=if(n[3]==n[1],n[^1],n[3..-1]));#n>1&&n[1]==n[2]} \\ _M. F. Hasler_, Jun 24 2016

%Y Cf. A115853.

%K nonn,base

%O 1,1

%A _Clark Kimberling_

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Last modified April 6 08:44 EDT 2020. Contains 333268 sequences. (Running on oeis4.)