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!)
A318698 a(n) is the smallest nonnegative integer of the same parity as n, not yet in the sequence, that shares a digit with a(n-1); a(0)=0. 1
0, 101, 10, 1, 12, 11, 14, 13, 16, 15, 18, 17, 70, 7, 72, 21, 2, 23, 20, 25, 22, 27, 24, 29, 26, 61, 6, 63, 30, 3, 32, 31, 34, 33, 36, 35, 38, 37, 74, 41, 4, 43, 40, 45, 42, 47, 44, 49, 46, 65, 50, 5, 52, 51, 54, 53, 56, 55, 58, 57, 76, 67, 60, 69, 62, 121, 28, 81, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Conjecture: This is a permutation of the nonnegative integers.

The one-digit integers appear in the following order: 0,1,7,2,6,3,4,5,8,9.

LINKS

Robert Israel, Table of n, a(n) for n = 0..10000

EXAMPLE

a(1)=101 since 101 is the smallest odd nonnegative integer not yet in the sequence that shares the digit 0 with a(0)=0;

a(2)=10 since 10 is the smallest even nonnegative integer not yet in the sequence that shares the digit 0 (and 1) with a(1)=101.

MAPLE

N:= 1000: # to stop before the first term > N

S0:= [seq(i, i=2..N, 2)]: S1:= [seq(i, i=1..N, 2)]:

D0:= map(t -> convert(convert(t, base, 10), set), S0):

D1:= map(t -> convert(convert(t, base, 10), set), S1):

A[0]:= 0: Da:= {0}: found:= true:

for n from 1 while found do

  found:= false;

  if n::even then

    for j from 1 to nops(D0) do

      if Da intersect D0[j] <> {} then

        found:= true;

        A[n]:= S0[j];

        Da:= D0[j];

        S0:= subsop(j=NULL, S0);

        D0:= subsop(j=NULL, D0);

        break

      fi

    od

  else

    for j from 1 to nops(D1) do

      if Da intersect D1[j] <> {} then

        found:= true;

        A[n]:= S1[j];

        Da:= D1[j];

        S1:= subsop(j=NULL, S1);

        D1:= subsop(j=NULL, D1);

        break

      fi

    od

  fi

od:

seq(A[i], i=0..n-2); # Robert Israel, Feb 05 2020

CROSSREFS

Cf. A107353, A297352, A297353.

Sequence in context: A256826 A036193 A126834 * A180236 A279149 A282065

Adjacent sequences:  A318695 A318696 A318697 * A318699 A318700 A318701

KEYWORD

nonn,base

AUTHOR

Enrique Navarrete, Aug 31 2018

STATUS

approved

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 May 14 19:53 EDT 2021. Contains 343903 sequences. (Running on oeis4.)