

A118212


Numbers n such that the reversal of all five numbers n^1, n^2, n^3 n^4 and n^5 are primes.


4



3244, 32440, 324400, 324886, 1109311, 1979137, 3244000, 3248860, 10212316, 10255493, 10282339, 10306511, 10503781, 10573126, 10657861, 10692107, 11093110, 11145841, 11171452, 19791370, 19855967, 19875058, 19912073
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OFFSET

1,1


COMMENTS

This sequence is infinite because if n is in the sequence then for all natural numbers m, 10^m*n is in the sequence.
110218462 is the smallest term n such that the reversal of n^6 is also prime.
A165698 is a subsequence of this sequence such that for each term n reversal(n^6)
is also prime. (End)


LINKS



EXAMPLE

3244 is in the sequence because reversal(3244^k) for k=1,2,...,5
are respectively 4423, 63532501, 48705383143, 692349908447011,
and 422250654361652953 and these five numbers are primes.


MATHEMATICA

Do[If[PrimeQ[FromDigits[Reverse[IntegerDigits[n]]]] && PrimeQ[FromDigits[Reverse[IntegerDigits[n^2]]]] && PrimeQ [FromDigits[Reverse[IntegerDigits[n^3]]]] && PrimeQ[FromDigits [Reverse[IntegerDigits[n^4]]]] && PrimeQ[FromDigits[Reverse [IntegerDigits[n^5]]]], Print[n]], {n, 32000000}]
Select[Range[20000000], And@@PrimeQ[FromDigits[Reverse[ IntegerDigits[ #]]]&/@ (#^Range[5])]&] (* Harvey P. Dale, Jan 17 2014 *)


CROSSREFS



KEYWORD

base,easy,nonn


AUTHOR



STATUS

approved



