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

1,1

Comments

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

Links

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

Example

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

Mathematica

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

Prog

(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

Crossrefs

Cf. A007500, A095179, A371653.

Sequence in context: A326715 A338925 A358761 * A089063 A339819 A247142

Adjacent sequences: A371651 A371652 A371653 * A371655 A371656 A371657

Keyword

nonn,base,easy

Author

César Eliud Lozada, Apr 01 2024

Status

approved