A229221 Numbers k such that k - (product of digits of k) is prime.

21, 23, 27, 29, 41, 43, 47, 49, 81, 83, 87, 89, 101, 103, 107, 109, 127, 141, 143, 149, 181, 187, 223, 227, 229, 241, 247, 251, 253, 263, 271, 277, 293, 299, 307, 343, 347, 349, 367, 383, 389, 401, 409, 413, 417, 419, 431, 433, 437, 439, 451, 457, 471, 473, 477, 479, 481, 487, 503, 509, 527, 529, 541

Offset: 1

Author

Derek Orr, Sep 16 2013

Keywords

• nonn
• base
• easy

Crossrefs

Cf. A157676.

Programs

Mathematica

fQ[n_] := Module[{q = n - Times @@ IntegerDigits[n]}, q > 0 && PrimeQ[q]]; Select[Range[500], fQ] (* T. D. Noe, Sep 17 2013 *)

PARI

for(n=1,10^3,d=digits(n);p=prod(i=1,#d,d[i]);if(isprime(n-p),print1(n,", "))) \\ Derek Orr, Apr 10 2015

Python

from sympy import isprime
def DP(n):
    p = 1
    for i in str(n):
        p *= int(i)
    return p
{print(n,end=', ') for n in range(10**3) if isprime(n-DP(n))}
## Simplified by Derek Orr, Apr 10 2015

Sage

[x for x in range(1000) if (x-prod(Integer(x).digits(base=10))) in Primes()] # Tom Edgar, Sep 18 2013

Extensions

More terms from Derek Orr, Apr 10 2015