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Primes p such that p^3 with the rightmost digit removed is also prime.
2

%I #12 Sep 08 2022 08:46:12

%S 3,17,53,113,157,233,257,277,353,359,379,397,677,877,997,1039,1217,

%T 1439,1613,1697,1879,1973,1997,2273,2417,2459,2777,3257,3413,3499,

%U 3517,3697,3779,4073,4157,4177,4339,4973,4999,5077,5197,5279,5639,5813,5897,6277,6379

%N Primes p such that p^3 with the rightmost digit removed is also prime.

%H Charles R Greathouse IV, <a href="/A258032/b258032.txt">Table of n, a(n) for n = 1..10000</a>

%e a(2) = 17 is prime: 17^3 = 4913. Removing rightmost digit gives 491 which is prime.

%e a(3) = 53 is prime: 53^3 = 148877. Removing rightmost digit gives 14887 which is prime.

%t Select[Prime[Range[1000]], PrimeQ[Floor[(#^3)/10]] &]

%o (PARI) forprime(p=1,10000, if(isprime(floor((p^3)/10)), print1(p,", ")))

%o (Magma) [p: p in PrimesUpTo(6500) |IsPrime(Floor(p^3/10))]; // _Vincenzo Librandi_, May 17 2015

%o (Haskell)

%o a258032 n = a258032_list !! (n-1)

%o a258032_list = filter ((== 1) . a010051' . flip div 10. (^ 3)) a000040_list

%o -- _Reinhard Zumkeller_, May 18 2015

%Y Cf. A000040, A024770, A052025, A137812, A227916, A227919.

%Y Cf. A010051.

%K nonn,base

%O 1,1

%A _K. D. Bajpai_, May 16 2015