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2 neighbours create a square (Posted on 2021-08-19) Difficulty: 3 of 5
Concatenating two consecutive integers 183 and 184
we get a six-digit number 183184, equalling square of 428.
List similar pairs, below 500,000 (final product).

How about the same task with a pair of a consecutve numbers
in a decreasing order?
Please provide a similar list (same constraints).

No Solution Yet Submitted by Ady TZIDON    
Rating: 4.0000 (2 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re: solution ++ | Comment 3 of 9 |
(In reply to solution ++ by Charlie)

There do appear to be fewer descending, but there is a pattern in the list of descending:  91, 9901, 999001


which leads to an infinite sequence

(10^2n - 10^n + 1)^2 = 10^4n - 2*10^3n + 3*10^2n - 2*10^n + 1

The squares have that pattern of 
9...980...029...980...01

  Posted by Jer on 2021-08-19 11:24:12
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