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A167187
Primes obtained from other primes by prefixing a 7.
5
73, 719, 743, 761, 773, 797, 7103, 7109, 7127, 7151, 7193, 7211, 7229, 7283, 7307, 7331, 7349, 7433, 7457, 7487, 7499, 7523, 7541, 7547, 7577, 7607, 7643, 7673, 7691, 7727, 7757, 7823, 7829, 7853, 7877, 7883, 7907, 7919, 7937, 71039, 71069, 71129, 71153
OFFSET
1,1
LINKS
EXAMPLE
7151 is a prime obtained by prefixing a 7 to the prime 151.
MATHEMATICA
Select[FromDigits[Join[{7}, IntegerDigits[#]]]&/@Prime[Range[250]], PrimeQ] (* Harvey P. Dale, Aug 08 2014 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Parthasarathy Nambi, Oct 29 2009
EXTENSIONS
a(11)-a(42) from Vincenzo Librandi, Nov 01 2009
Corrected (a(15)=7307 inserted) by Harvey P. Dale, Aug 08 2014
STATUS
approved