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 A243408 Primes p such that 10p-1, 10p-3, 10p-7 and 10p-9 are all prime. 0
 2, 11, 83, 149, 347, 1301, 1607, 2531, 6299, 7727, 8273, 17117, 20183, 21737, 24371, 26669, 39227, 40277, 53951, 54917, 63347, 66359, 66467, 73637, 82217, 82373, 101537, 102251, 106397, 106871, 117203, 132971, 134033, 135221, 140237, 144701, 146141, 151433, 152597 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This is a subsequence of A064975. LINKS Table of n, a(n) for n=1..39. EXAMPLE 2 is prime, 10*2-1 = 19 is prime, 10*2-3 = 17 is prime, 10*2-7 = 13 is prime, 10*2-9 = 11 is prime. Thus 2 is a member of this sequence. MATHEMATICA Select[ Range@ 153000], PrimeQ[#] && PrimeQ[10#-1] && PrimeQ[10#-3] && PrimeQ[10#-7] && PrimeQ[10#-9] &] (* Robert G. Wilson v, Jun 06 2014 *) PROG (Python) import sympy from sympy import isprime from sympy import prime {print(prime(n), end=', ') for n in range(1, 10**5) if isprime(10*prime(n)-1) and isprime(10*prime(n)-3) and isprime(10*prime(n)-7) and isprime(10*prime(n)-9)} (PARI) for(n=1, 10^5, if(ispseudoprime(10*prime(n)-1) && ispseudoprime(10*prime(n)-3) && ispseudoprime(10*prime(n)-7) && ispseudoprime(10*prime(n)-9), print1(prime(n), ", "))) CROSSREFS Cf. A067267, A064975. Sequence in context: A209094 A293574 A322644 * A352655 A104086 A143140 Adjacent sequences: A243405 A243406 A243407 * A243409 A243410 A243411 KEYWORD nonn AUTHOR Derek Orr, Jun 04 2014 STATUS approved

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Last modified June 17 19:57 EDT 2024. Contains 373463 sequences. (Running on oeis4.)