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A309248
Primes p such that p * (sum of digits of p) - 2 is prime.
2
2, 3, 5, 7, 23, 29, 83, 89, 113, 131, 157, 173, 179, 191, 197, 199, 223, 281, 283, 311, 353, 359, 397, 401, 443, 467, 557, 593, 797, 809, 821, 827, 829, 863, 887, 977, 997, 1031, 1033, 1093, 1109, 1163, 1187, 1259, 1361, 1433, 1451, 1471, 1549, 1637, 1657, 1699
OFFSET
1,1
LINKS
EXAMPLE
2 is in the sequence because 2*(2)-2 = 2 prime.
23 is in the sequence because 23*(2+3)-2 = 113 prime.
PROG
(SageMath)
def isA309248(p):
s = sum(p.digits())
return is_prime(p * s - 2)
[p for p in prime_range(1000) if isA309248(p)]
CROSSREFS
Sequence in context: A210110 A235144 A235126 * A267014 A113611 A038925
KEYWORD
nonn,base
AUTHOR
Hauke Löffler, Jul 18 2019
STATUS
approved