A371654 Numbers that are not multiples of 10 and that yield a prime if their digits are arranged in ascending order.

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 32, 37, 47, 59, 67, 71, 73, 74, 76, 79, 89, 91, 92, 95, 97, 98, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 157, 167, 172, 173, 175, 176, 179, 193, 194, 197, 199, 203, 209, 217, 223, 227, 229, 232, 233, 239, 257

Offset: 1

Author

César Eliud Lozada, Apr 01 2024

Keywords

• nonn
• base
• easy

Comments

If N is a term then all numbers with the same digits as N are terms too.

Examples

			91 is a term because arranging its digits in ascending order yields 19, which is a prime.
		

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007500, A095179, A371653.

Programs

Mathematica

Select[Range[500],  Mod[#, 10] != 0 && PrimeQ[FromDigits[Sort[IntegerDigits[#]]]] &]

Python

from sympy import isprime
def ok(n): return n%10 and isprime(int("".join(sorted(str(n)))))
print([k for k in range(260) if ok(k)]) # Michael S. Branicky, Apr 01 2024

Python

from itertools import count, islice, combinations_with_replacement
from sympy import isprime
from sympy.utilities.iterables import multiset_permutations
def A371654_gen(): # generator of terms
    for l in count(1):
        xlist = []
        for p in combinations_with_replacement('0123456789',l):
            if isprime(int(''.join(p))):
                xlist.extend(int(''.join(d)) for d in multiset_permutations(p) if d[0] != '0' and d[-1] != '0')
        yield from sorted(xlist)
A371654_list = list(islice(A371654_gen(),20)) # Chai Wah Wu, Apr 10 2024