A238136 Primes p such that p^4-p^3+1 and p^4-p^3-1 are also primes.
1429, 5827, 7411, 9601, 12601, 18457, 20011, 20521, 24919, 25999, 28591, 29947, 33211, 33349, 36037, 38149, 41227, 42649, 43579, 45307, 46099, 49999, 52057, 52387, 54319, 59107, 59197, 59629, 67891, 70951, 73477, 74761, 75037, 81157, 92041, 93607, 114889
Offset: 1
Keywords
Examples
1429 is in the sequence because 1429, (1429^4-1429^3+1) and (1429^4-1429^3-1) are all primes.
Links
- K. D. Bajpai, Table of n, a(n) for n = 1..2918
Programs
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Maple
KD := proc() local a, b,d; a:=ithprime(n); b:= a^4-a^3+1;d:=a^4-a^3-1; if isprime (b) and isprime(d) then RETURN (a); fi; end: seq(KD(), n=1..20000);
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Mathematica
Select[Prime[Range[3000]],PrimeQ[#^4-#^3+1]&&PrimeQ[#^4-#^3-1]&] c=0;a=2;Do[k=Prime[n]; If[PrimeQ[k^4-k^3+1] &&PrimeQ[k^4-k^3-1], c=c+1; Print[c," ",k]], {n,1,2000000}]; pQ[n_]:=Module[{c=n^4-n^3},AllTrue[c+{1,-1},PrimeQ]]; Select[Prime[ Range[ 11000]],pQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Oct 19 2014 *)
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PARI
s=[]; forprime(p=2, 120000, if(isprime(p^4-p^3+1) && isprime(p^4-p^3-1), s=concat(s, p))); s \\ Colin Barker, Feb 18 2014