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.

A348699 Primes with a prime number of prime digits.

Original entry on oeis.org

23, 37, 53, 73, 127, 137, 157, 173, 223, 227, 229, 233, 239, 251, 257, 263, 271, 277, 283, 293, 307, 313, 317, 331, 337, 347, 353, 359, 367, 373, 379, 383, 397, 433, 457, 503, 521, 523, 547, 557, 563, 571, 577, 587, 593, 653, 673, 677, 727, 733, 739, 743, 751, 757, 773, 787, 797
Offset: 1

Views

Author

Jens Ahlström, Oct 30 2021

Keywords

Crossrefs

Intersection of A000040 and A092619.
Cf. A217090.

Programs

  • Mathematica
    Select[Range[800], And @@ PrimeQ[{#, Count[IntegerDigits[#], ?PrimeQ]}] &] (* _Amiram Eldar, Nov 04 2021 *)
  • Python
    from sympy import isprime as i
    from sympy import primerange as p
    print([x for x in p(1, 800) if i(len([d for d in str(x) if i(int(d))]))])
    
  • Python
    from sympy import isprime
    def ok(n): return isprime(n) and isprime(sum(1 for d in str(n) if d in "2357"))
    print([k for k in range(800) if ok(k)]) # Michael S. Branicky, Jun 26 2025