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Ulam numbers II (Posted on 2017-11-18)

There is a finite number of Ulam numbers n, such that n+1 is also an Ulam number.

List all such pairs.

Submitted by Ady TZIDON

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Solution: (Hide)

1,2,3,47 are the only values of x such that x and x+1 are both Ulam numbers.
No proof of completeness.
Checked for the first 28 billion Ulam numbers as of 2016.(OEIS)

Comments: ( You must be logged in to post comments.)

	Subject	Author	Date
	computer "solution"	Charlie	2017-11-18 16:10:30

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