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A106041 Numbers n such that n*prime(n)-1 is a perfect square. 2
1, 10, 50, 4946, 397706, 1243141, 3445873, 9210805, 805715770, 1542576890 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Next term, if it exists, is > 400000. - 397706 from Emeric Deutsch, May 31 2005
a(11) > pi(4*10^12). - Donovan Johnson, Oct 22 2010
a(11) > pi(1.9*10^14). - Giovanni Resta, May 21 2018
LINKS
EXAMPLE
1*2-1=1^2
10*29-1=17^2
50*229-1=107^2
4946*47981-1=15405^2
CROSSREFS
Sequence in context: A216156 A072296 A143558 * A370737 A264044 A143855
KEYWORD
nonn
AUTHOR
Zak Seidov, May 06 2005
EXTENSIONS
397706 from Emeric Deutsch, May 31 2005
4 more terms from Ryan Propper, Oct 16 2005
a(10) from Donovan Johnson, Oct 22 2010
STATUS
approved

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Last modified July 12 14:24 EDT 2024. Contains 374251 sequences. (Running on oeis4.)