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A167722
Squares that become prime numbers when prefixed with a 7.
1
1, 9, 121, 529, 841, 1089, 1849, 3721, 4489, 4761, 5041, 5329, 6561, 7569, 8649, 9801, 10609, 12321, 17161, 23409, 28561, 32041, 32761, 33489, 39601, 45369, 49729, 51529, 54289, 61009, 62001, 63001, 66049, 69169, 71289, 76729, 88209, 94249
OFFSET
1,2
COMMENTS
For obvious reasons, all terms are odd. - Harvey P. Dale, Sep 30 2012
Subsequence of squares of A032670. - Michel Marcus, Jun 22 2016
LINKS
MATHEMATICA
Select[Range[1, 400, 2]^2, PrimeQ[FromDigits[Join[{7}, IntegerDigits[#]]]]&] (* Harvey P. Dale, Sep 30 2012 *)
CROSSREFS
Cf. A032670.
Sequence in context: A157930 A259836 A017102 * A103930 A302941 A183514
KEYWORD
base,nonn
AUTHOR
Claudio Meller, Nov 10 2009
STATUS
approved