cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A243408 Primes p such that 10*p-1, 10*p-3, 10*p-7 and 10*p-9 are all prime.

Original entry on oeis.org

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
Offset: 1

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Author

Derek Orr, Jun 04 2014

Keywords

Comments

This is a subsequence of A064975.

Examples

			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.
		

Crossrefs

Programs

  • Mathematica
    Select[ Range@ 153000,PrimeQ[#] && PrimeQ[10#-1] && PrimeQ[10#-3] && PrimeQ[10#-7] && PrimeQ[10#-9] &] (* Robert G. Wilson v, Jun 06 2014 *)
    Select[Prime[Range[15000]],AllTrue[10#-{1,3,7,9},PrimeQ]&] (* Harvey P. Dale, Aug 18 2024 *)
  • 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),", ")))
  • 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)}