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 A130737 Primes p such that p+2, p*(p+2)+18 and p*(p+2)+20 are also prime. 2
 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 (list; graph; refs; listen; history; text; internal format)
 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: A142733 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

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Last modified February 2 18:34 EST 2023. Contains 360023 sequences. (Running on oeis4.)