login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A276105 Lexicographically first sequence (with no duplicate term) where all the digits "2" are separated by two digits. 0

%I

%S 1,2,3,4,20,5,21,6,23,7,24,8,25,9,26,12,10,27,32,11,28,42,13,29,52,14,

%T 200,201,203,204,205,206,207,208,209,210,211,213,214,215,216,217,218,

%U 219,230,231,233,234,235,236,237,238,239,240,241,243,244,245,246,247,248,249

%N Lexicographically first sequence (with no duplicate term) where all the digits "2" are separated by two digits.

%C The sequence is started with a(1)=1 and always extended with the smallest integer not yet used that does not lead to a contradiction.

%e To match the infinite digit-pattern 2..2..2..2..2..2.. (etc.) one must use the integer 20 after the fourth term (which is 4), then use the integer 5, then use the integer 21, then use the integer 6, then use the integer 23 (as 22 is forbidden: no integer with consecutive 2's is allowed), etc.

%K nonn,base

%O 1,2

%A _Eric Angelini_, Aug 18 2016

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 18 03:25 EDT 2021. Contains 348065 sequences. (Running on oeis4.)