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!)
A087553 Squares in which the neighboring digits differ at most by 1. Neighbors of 1 are 0 and 2, neighbors of 0 are 1 and 9. 0
1, 4, 9, 100, 121, 676, 900, 10000, 12100, 12321, 90000, 1000000, 1210000, 1232100, 1234321, 9000000, 100000000, 121000000, 123210000, 123432100, 123454321, 900000000, 10000000000, 11122233444, 12100000000, 12321000000, 12343210000 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
The sequence is infinite with trivial terms like 10^(2k) and 9*10^(2k). Conjecture: There are infinitely many nontrivial terms.
LINKS
EXAMPLE
12321, 1345678987654321 are members.
CROSSREFS
Sequence in context: A069707 A129967 A182020 * A061850 A061459 A061869
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Sep 13 2003
EXTENSIONS
More terms from Sascha Kurz, Sep 22 2003
STATUS
approved

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 May 26 05:37 EDT 2024. Contains 372807 sequences. (Running on oeis4.)