A059007 Numbers m such that m^2 reversed is a prime.

4, 14, 19, 28, 32, 37, 38, 40, 41, 62, 85, 89, 95, 97, 106, 119, 136, 139, 140, 190, 193, 196, 266, 271, 274, 277, 280, 281, 313, 316, 320, 325, 328, 331, 334, 335, 353, 355, 361, 362, 370, 373, 377, 380, 383, 397, 398, 400, 401, 403, 410, 412, 421, 434, 439

Offset: 1

Author

Robert G. Wilson v, Jan 16 2001

Keywords

• nonn
• base

Examples

			28 is in the sequence because the reverse of 28^2 is 487 which is a prime. - _Indranil Ghosh_, Feb 10 2017
		

Links

• Indranil Ghosh, Table of n, a(n) for n = 1..10000 (terms 0..1000 from T. D. Noe)

Crossrefs

Cf. A007488.

Numbers m such that m^k reversed is a prime: A059008 (k=3), A059205 (k=4), A059206 (k=5), A059207 (k=6), A059208 (k=7), A059209 (k=8), A059210 (k=9), A059211 (k=10), A059212 (k=11), A059213 (k=12).

Programs

Magma

[n: n in [1..500] | IsPrime(Seqint(Reverse(Intseq(n^2))))]; // Marius A. Burtea, Jan 12 2019

Mathematica

Select[ Range[ 1000 ], PrimeQ[ ToExpression[ StringReverse[ ToString[ #^2 ] ] ] ] & ]
Select[Range[500],PrimeQ[IntegerReverse[#^2]]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Aug 10 2019 *)

PARI

isok(n) = isprime(fromdigits(Vecrev(digits(n^2)))); \\ Michel Marcus, Jan 12 2019