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.

User: Mohd Anwar Jamal Faiz

Mohd Anwar Jamal Faiz's wiki page.

Mohd Anwar Jamal Faiz has authored 2 sequences.

A385056 Prime numbers whose digit product is a positive cube.

Original entry on oeis.org

11, 139, 181, 193, 241, 389, 421, 811, 839, 881, 983, 1181, 1193, 1319, 1777, 1811, 1913, 1931, 1999, 2141, 2221, 2269, 2411, 2663, 3119, 3191, 3313, 3331, 3463, 3643, 3833, 3889, 3911, 4211, 4363, 4441, 4691, 6229, 6263, 6343, 6491, 6661, 7177, 7717, 7877, 8111
Offset: 1

Views

Author

Mohd Anwar Jamal Faiz, Jun 16 2025

Keywords

Crossrefs

Intersection of A000040 and A237767.
Subsequence of A038618.
Cf. A184328.

Programs

  • Maple
    q:= n-> isprime(n) and (p-> p>0 and iroot(p, 3)^3=p)(mul(i, i=convert(n, base, 10))):
select(q, [$2..10000])[];  # Alois P. Heinz, Jun 16 2025
  • Mathematica
    q[n_] := Module[{pd = Times @@ IntegerDigits[n]}, pd > 0 && IntegerQ[Surd[pd, 3]]]; Select[Prime[Range[1300]], q] (* Amiram Eldar, Jun 16 2025 *)
  • PARI
    isok(k) = if (isprime(k), my(p=vecprod(digits(k))); p && ispower(p, 3)); \\ Michel Marcus, Jun 16 2025
  • Python
    from sympy import primerange, integer_nthroot
from math import prod
is_cube = lambda n: n > 0 and integer_nthroot(n, 3)[1]
digit_product = lambda n: prod(map(int, str(n)))
cubigit_primes = [p for p in primerange(2, 100000) if is_cube(dp := digit_product(p))]
print(cubigit_primes)

A384735 Numbers that are prime or end in a prime number (of any length).

Original entry on oeis.org

2, 3, 5, 7, 11, 12, 13, 15, 17, 19, 22, 23, 25, 27, 29, 31, 32, 33, 35, 37, 41, 42, 43, 45, 47, 52, 53, 55, 57, 59, 61, 62, 63, 65, 67, 71, 72, 73, 75, 77, 79, 82, 83, 85, 87, 89, 92, 93, 95, 97, 101, 102, 103, 105, 107, 109, 111, 112, 113, 115, 117
Offset: 1

Views

Author

Mohd Anwar Jamal Faiz, Jun 08 2025

Keywords

Comments

If k is a term, so is m*10^A055642(k) + k for all m > 0. - Michael S. Branicky, Jun 10 2025

Examples

			2, 3, 5, 7 and 11 are terms since they are prime.
15 is a term since it ends in the prime 5.
111 is a term since it ends in the prime 11.

Links

Crossrefs

Cf. A000040, A033664, A055642.
Contains A017293, A017305, A017329, A017353.

Programs

  • Maple
    q:= n-> isprime(n) or (k-> k>1 and q(n mod 10^(k-1)))(length(n)):
select(q, [$1..150])[];  # Alois P. Heinz, Jun 08 2025
  • Mathematica
    q[n_] := AnyTrue[Range[1, IntegerLength[n]-1], PrimeQ[Mod[n, 10^#]] &]; Select[Range[120], PrimeQ[#] || q[#] &] (* Amiram Eldar, Jun 10 2025 *)
  • PARI
    isok(x) = my(y=x, nb=0); while(y>1, y/=10; nb++; if (isprime(x%(10^nb)), return(1))); \\ Michel Marcus, Jun 10 2025
  • Python
    from sympy import isprime
def ok(n):
    s = str(n)
    return any(isprime(int(s[i:])) for i in range(len(s)))
print([k for k in range(118) if ok(k)])

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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