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A106066
Primes p such that 1*p+20 and 20*p+1 are primes.
2
3, 23, 41, 47, 53, 59, 107, 131, 137, 173, 179, 191, 251, 263, 293, 311, 443, 467, 503, 599, 641, 971, 977, 1013, 1049, 1151, 1277, 1301, 1307, 1409, 1427, 1433, 1451, 1559, 1607, 1721, 1913, 1973, 1979, 2069, 2111, 2141, 2267, 2417, 2693, 2729, 2777, 2999
OFFSET
1,1
MATHEMATICA
Select[Prime[Range[220]], PrimeQ[20#+1]&&PrimeQ[1#+20]&]
PROG
(Magma) [p: p in PrimesUpTo(10000)| IsPrime(p+20) and IsPrime(20*p+1)] // Vincenzo Librandi, Nov 13 2010
CROSSREFS
Sequence in context: A106892 A370601 A116893 * A281551 A167216 A309935
KEYWORD
nonn
AUTHOR
Zak Seidov, May 07 2005
EXTENSIONS
More terms from Vincenzo Librandi, Apr 01 2010
STATUS
approved