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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

Table of n, a(n) for n=0..26.

EXAMPLE

12321, 1345678987654321 are members.

CROSSREFS

Sequence in context: A069707 A129967 A182020 * A061850 A061459 A061869

Adjacent sequences:  A087550 A087551 A087552 * A087554 A087555 A087556

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Sep 13 2003

EXTENSIONS

More terms from Sascha Kurz, Sep 22 2003

STATUS

approved

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Last modified February 23 21:20 EST 2020. Contains 332195 sequences. (Running on oeis4.)