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

Offset: 1

Author

Amarnath Murthy, Sep 13 2003

Keywords

• base
• nonn

Comments

The sequence is infinite with trivial terms like 10^(2k) and 9*10^(2k). Conjecture: There are infinitely many nontrivial terms.

Examples

			12321, 1345678987654321 are terms.
		

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..63

Crossrefs

Intersection of A000290 and A376425.

Extensions

More terms from Sascha Kurz, Sep 22 2003

Offset changed and 0 inserted by Andrew Howroyd, Sep 22 2024