OFFSET
1,1
EXAMPLE
1!+3!+5! = 127 and 127 is prime, so 135 appears in the sequence.
PROG
(PARI) digfac(n)=local(s=0); while(n, s=s+((n%10)!); n=n\10); return(s)
for(n=1, 1000, if(isprime(digfac(n)), print1(n, ", ")))
(Python)
from itertools import count, islice, combinations_with_replacement
from math import factorial
from sympy import isprime
from sympy.utilities.iterables import multiset_permutations
def A165451_gen(): # generator of terms
for l in count(0):
for i in range(1, 10):
fi = factorial(i)
yield from sorted(int(str(i)+''.join(map(str, k))) for j in combinations_with_replacement(range(10), l) for k in multiset_permutations(j) if isprime(fi+sum(map(factorial, j))))
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Rémy Sigrist, Sep 20 2009
STATUS
approved