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A245010
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Numbers k such that k*prime(k) + 43 is a square.
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0
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OFFSET
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1,1
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LINKS
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EXAMPLE
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2 * 3 + 43 = 7^2;
6 * 13 + 43 = 11^2;
13 * 41 + 43 = 24^2;
57 * 269 + 43 = 124^2;
1614 * 13669 + 43 = 4697^2;
3686 * 34501 + 43 = 11277^2;
735417 * 11144513 + 43 = 2862842^2.
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MATHEMATICA
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Select[Range[800000], IntegerQ[Sqrt[# Prime[#]+43]]&] (* Harvey P. Dale, Aug 04 2018 *)
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PROG
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(Sage)
L = primes_first_n(1000000)
[n for n in [1..999999] if is_square(n*L[n-1]+43)] # Tom Edgar, Jul 10 2014
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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