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!)
A342215 Two successive terms always share a common "digit pattern" (see the Comments section). The successive "common digit patterns", concatenated, reproduce the successive terms of the sequence, concatenated. 1

%I

%S 1,10,100,101,1201,301,12,20,104,13,30,102,14,21,2,200,103,410,341,3,

%T 203,105,210,421,1242,112,204,50,106,310,34,41,107,230,43,114,31,23,

%U 205,303,113,108,305,25,121,109,40,24,123,15,120,42,1142,211,26,207,140,45,250,110,610,36,131,160,302,134,4

%N Two successive terms always share a common "digit pattern" (see the Comments section). The successive "common digit patterns", concatenated, reproduce the successive terms of the sequence, concatenated.

%C A "common pattern" shared by two successive integers A and B is a string of digits present in both A and B. For example, if A = 1 and B = 10 the common pattern is "1"; if A = 2021 and B = 302 the common pattern is "02".

%C We allow the successive terms A and B to share more than one pattern, but only in the case of a single shared longer string of digits - longer than the other possible strings; as A = 2021 and B = 231 share both the strings "2" and "1", which are of the same length, B cannot follow A in the sequence. As A = 2021 and B = 2031 share both the strings "20" and "1" and as the string "20" is longer than the string "1", B could follow A in the sequence (the "common pattern" would be "20" here).

%C This "common pattern" idea was imagined to inspire people having almost no mathematical skills - only two eyes (or one single eye) and a pencil.

%C Caveat: to reduce the computing time, no term > 10000 was tested.

%C Given the doubts about this sequence, please do NOT add a b-file. _N. J. A. Sloane_, Mar 14 2021

%H Carole Dubois, <a href="/A342215/a342215.txt">Conjectured table of n, a(n) for n = 1..789</a>

%e The first ten terms are 1, 10, 100, 101, 1201, 301, 12, 20, 104, 13.

%e The "common patterns" are 1 10 10 01 01 1 2 0 1 and their concatenation is 1101001011201 - which is exactly the start of the concatenation of the sequence's terms.

%Y Cf. A152603

%K base,nonn

%O 1,2

%A _Eric Angelini_ and _Carole Dubois_, Mar 05 2021

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 July 29 23:58 EDT 2021. Contains 346346 sequences. (Running on oeis4.)