The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A369303 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest unused number whose string value contains the comma transform (cf. A367360) of the previous two terms. 1

%I #11 Jan 19 2024 08:14:08

%S 1,2,12,21,22,112,121,210,120,10,11,13,110,31,3,113,131,231,122,111,

%T 211,123,114,310,43,4,34,143,41,134,115,141,51,15,116,151,61,16,117,

%U 161,71,17,118,171,81,18,119,181,91,19,311,93,190,312,23,220,32,30,223,20,132,14,212,42,24,221

%N a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest unused number whose string value contains the comma transform (cf. A367360) of the previous two terms.

%C The sequence is conjectured to be a permutation of the positive integers. The fixed points begin 1, 2, 10, 11, 2863, 3164, 3545, 3947, 6835, 6947, 7052, ... although it is likely there are infinitely more.

%H Scott R. Shannon, <a href="/A369303/b369303.txt">Table of n, a(n) for n = 1..10000</a>

%H Scott R. Shannon, <a href="/A369303/a369303.png">Image of the first one million terms</a>. The green line is a(n) = n.

%e a(3) = 12 as the comma transform of 1 and 2 is 12.

%e a(6) = 112 as the comma transform of 21 and 22 is 12, but 12 has already appeared so the next lowest unused number to contain '12' is 112.

%Y Cf. A367360, A121805, A367362.

%K nonn,base,look

%O 1,2

%A _Scott R. Shannon_, Jan 19 2024

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 11 05:33 EDT 2024. Contains 373289 sequences. (Running on oeis4.)