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A237995 Primes p such that p^4 - p^3 - 1 is also prime.

%I A237995 #21 Feb 18 2014 09:50:05
%S A237995 2,3,5,11,17,53,59,101,103,151,157,167,193,197,239,353,379,397,419,
%T A237995 433,467,479,503,599,641,659,661,743,787,881,907,911,983,1049,1109,
%U A237995 1123,1153,1201,1229,1291,1307,1373,1399,1429,1531,1601,1621,1663,1747,1753
%N A237995 Primes p such that  p^4 - p^3 - 1 is also prime.
%H A237995 K. D. Bajpai, <a href="/A237995/b237995.txt">Table of n, a(n) for n = 1..3700</a>
%e A237995 5 is in the sequence because 5 is prime and 5^4 - 5^3 - 1 = 499 is also prime.
%e A237995 17 is in the sequence because 17 is prime and 17^4 - 17^3 - 1 = 78607 is also prime.
%p A237995 KD := proc() local a,b; a:= ithprime(n); b:= a^4-a^3-1;if isprime(b) then RETURN (a); fi; end: seq(KD(), n=1..400);
%t A237995 c = 0; a = 2; Do[k = Prime[n]; If[PrimeQ[k^4 - k^3 - 1], c = c + 1;  Print[c, " ", k]], {n, 100000}]; (* Bajpai *)
%t A237995 Select[Prime[Range[200]], PrimeQ[#^4 - #^3 - 1] &] (* _Alonso del Arte_, Feb 17 2014 *)
%o A237995 (PARI) s=[]; forprime(p=2, 2000, if(isprime(p^4-p^3-1), s=concat(s, p))); s \\ _Colin Barker_, Feb 17 2014
%Y A237995 Cf. A000040, A237639, A237641, A237642.
%K A237995 nonn
%O A237995 1,1
%A A237995 _K. D. Bajpai_, Feb 16 2014