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.

Showing 1-1 of 1 results.

A375313 Primes p such that the prime triple (p, p+2 or p+4, p+6) generates a prime number when the digits are concatenated.

Original entry on oeis.org

5, 11, 17, 41, 307, 1447, 2377, 3163, 3253, 3457, 4783, 5653, 6547, 7873, 9007, 11171, 11827, 16061, 16187, 19423, 20743, 20897, 21313, 21517, 26107, 27103, 29017, 29021, 33613, 34123, 34841, 34843, 36011, 38917, 39227, 40693, 41177, 47737, 51341, 55213
Offset: 1

Views

Author

James S. DeArmon, Aug 11 2024

Keywords

Examples

			The first term is 5, since the prime triple (p,p+2,p+6) or (5,7,11) generates the prime number 5711 when the digits are concatenated. The fifth term is 307, since the prime triple (p,p+4,p+6) or (307,311,313) generates the prime number 307311313 when the digits are concatenated.
		

Crossrefs

Cf. A174858.

Programs

  • Mathematica
    Select[Partition[Prime[Range[6000]],3,1],#[[3]]-#[[1]]==6&&PrimeQ[FromDigits[Flatten[ IntegerDigits/@ #]]]&][[;;,1]] (* Harvey P. Dale, Aug 21 2024 *)
  • Python
    from itertools import islice
    from sympy import isprime, nextprime
    def agen(): # generator of terms
        p, q, r = 2, 3, 5
        while True:
            if (q == p+2 or q == p+4) and r == p+6:
                if isprime(int(str(p) + str(q) + str(r))):
                    yield p
            p, q, r = q, r, nextprime(r)
    print(list(islice(agen(), 41))) # Michael S. Branicky, Aug 18 2024
Showing 1-1 of 1 results.