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A178551
Primes with exactly two 2's.
5
223, 227, 229, 1223, 1229, 2027, 2029, 2129, 2203, 2207, 2213, 2237, 2239, 2243, 2251, 2267, 2269, 2273, 2281, 2287, 2293, 2297, 2423, 2521, 2621, 2729, 2927, 3221, 3229, 4229, 5227, 6221, 6229, 7229, 8221, 9221, 9227, 10223, 12203, 12211, 12239
OFFSET
1,1
LINKS
PROG
(Python)
from sympy import isprime
print([i for i in range(10000) if str(i).count('2') == 2 and isprime(i)]) # Daniel Starodubtsev, Mar 29 2020
KEYWORD
nonn,base
AUTHOR
Lekraj Beedassy, May 29 2010
STATUS
approved