A130737 Primes p such that p+2, p*(p+2)+18 and p*(p+2)+20 are also prime.

419, 2309, 16631, 17387, 17597, 22637, 32297, 49937, 51239, 61151, 66947, 122387, 124907, 136751, 148721, 148931, 152459, 182027, 183917, 189251, 203909, 209579, 228521, 246707, 251789, 291689, 324617, 371027, 388961, 408701, 409289

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Maple

a:=proc(n)local p: p:=ithprime(n): if isprime(p+2)=true and isprime(p*(p+2)+18)=true and isprime(p*(p+2)+20)=true then p else end if end proc: seq(a(n), n= 1..40000); # Emeric Deutsch, Jul 28 2007

Mathematica

Select[Prime[Range[60000]], PrimeQ[#+2] && PrimeQ[#*(#+2)+18] && PrimeQ[#*(#+2)+20] &] (* G. C. Greubel, Mar 03 2019 *)

Prog

(PARI) {isok(n) = isprime(n) && isprime(n+2) && isprime(n*(n+2)+18) && isprime(n*(n+2)+20)};
forprime(n=1, 500000, if(isok(n), print1(n", "))) \\ G. C. Greubel, Mar 03 2019
(Magma) [n: n in [1..500000] | IsPrime(n) and IsPrime(n+2) and IsPrime(n*(n+2)+18) and IsPrime(n*(n+2)+20)]; // G. C. Greubel, Mar 03 2019
(Sage) [n for n in (1..500000) if is_prime(n) and is_prime(n+2) and is_prime(n*(n+2)+18) and is_prime(n*(n+2)+20)] # G. C. Greubel, Mar 03 2019
(GAP) Filtered([1..500000], k-> IsPrime(k) and IsPrime(k+2) and IsPrime(k*(k+2)+18) and IsPrime(k*(k+2)+20)) # G. C. Greubel, Mar 03 2019

Crossrefs

Cf. A001359, A130736.

Sequence in context: A364359 A060230 A255097 * A242326 A298699 A187218

Adjacent sequences: A130734 A130735 A130736 * A130738 A130739 A130740

Keyword

nonn

Author

Ray G. Opao, Jul 06 2007

Extensions

More terms from Emeric Deutsch, Jul 28 2007

Status

approved