A167722 Squares that become prime numbers when prefixed with a 7.

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

G. C. Greubel, Table of n, a(n) for n = 1..10000

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

Adjacent sequences: A167719 A167720 A167721 * A167723 A167724 A167725

Keyword

base,nonn

Author

Claudio Meller, Nov 10 2009

Status

approved