

A088619


Numbers k such that the concatenation of 1, k and k^2 is prime.


2



3, 11, 21, 29, 39, 47, 59, 69, 101, 111, 131, 149, 171, 183, 197, 213, 231, 243, 249, 251, 297, 299, 317, 323, 329, 369, 387, 401, 411, 423, 431, 461, 501, 521, 527, 533, 537, 539, 543, 593, 651, 657, 669, 717, 741, 743, 779, 819, 867, 869, 873, 897, 939, 981
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OFFSET

1,1


LINKS



EXAMPLE

3 is a member as 139 is a prime. 11 is a member as 111121 (concatenation of 1,11 and 121) is prime.


MATHEMATICA

Select[ Range[1000], PrimeQ[ FromDigits[ Join[ IntegerDigits[ #^0], IntegerDigits[ # ], IntegerDigits[ #^2]]]] &]


CROSSREFS



KEYWORD

base,nonn


AUTHOR



EXTENSIONS



STATUS

approved



