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A167716
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Squares that become a prime number when prefixed with a 1.
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1
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1, 9, 49, 81, 289, 361, 1369, 1681, 2401, 2601, 2809, 3249, 3721, 4489, 5329, 6561, 6889, 7569, 7921, 9801, 10609, 14161, 14641, 19321, 19881, 21609, 22201, 25921, 32761, 35721, 36481, 40401, 41209, 47089, 49729, 52441, 61009, 67081, 77841
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OFFSET
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1,2
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COMMENTS
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LINKS
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MATHEMATICA
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Select[Range[1, 700, 2]^2, PrimeQ[FromDigits[Join[{1}, IntegerDigits[#]]]] &] (* G. C. Greubel, Jun 21 2016 *)
Select[Range[1, 701, 2]^2, PrimeQ[10^IntegerLength[#]+#]&] (* Harvey P. Dale, Mar 31 2019 *)
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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STATUS
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approved
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