A371352 Prime numbers such that the sum of their prime digits is equal to the sum of their nonprime digits.

167, 211, 541, 617, 761, 853, 1021, 1201, 1423, 1559, 1607, 1973, 2011, 2143, 2341, 2383, 2833, 3467, 3719, 3823, 3917, 4051, 4231, 4637, 4673, 5261, 5443, 5519, 5591, 6473, 6521, 6701, 7193, 7643, 7687, 7867, 8053, 8233, 8677, 9137, 9173, 9371, 9551

Offset

1,1

Links

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

Example

9173 is a term because it is a prime number whose prime digits and nonprime digits have the same sum: 3 + 7 = 1 + 9 = 10.

Mathematica

Select[Prime[Range[1200]], Plus @@ Select[d = IntegerDigits[#], PrimeQ[#1] &] == Plus @@ Select[d, ! PrimeQ[#1] &] &] (* Amiram Eldar, Mar 22 2024 *)

Prog

(Python)
from sympy import isprime
def ok(n):
    if not isprime(n): return False
    s, sums = str(n), [0, 0]
    for c in s: sums[int(c in "2357")] += int(c)
    return sums[0] == sums[1]
print([k for k in range(10**4) if ok(k)]) # Michael S. Branicky, Apr 23 2024

Crossrefs

Cf. A000040, A156343 (equal number of prime and nonprime digits).

Sequence in context: A273549 A299379 A097400 * A142664 A247941 A338343

Adjacent sequences: A371349 A371350 A371351 * A371353 A371354 A371355

Keyword

nonn,base,changed

Author

Gonzalo Martínez, Mar 19 2024

Status

approved