

A069791


Primes which yield primes each time the process of removing two outermost digits is carried out until finally a two digit prime (possibly with a leading 0) is obtained.


0



1021, 1031, 1033, 1039, 1051, 1117, 1171, 1193, 1231, 1237, 1291, 1297, 1319, 1373, 1433, 1439, 1471, 1531, 1597, 1613, 1619, 1733, 1831, 1973, 1979, 2027, 2029, 2039, 2053, 2111, 2113, 2131, 2137, 2179, 2237, 2239, 2293, 2297, 2311, 2371
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OFFSET

1,1


LINKS



EXAMPLE

101737 is a member as the number obtained by removing the first and the last digit 0173 is a prime and further removing the first and the last digit gives another prime 17.


MATHEMATICA

Select[Prime[Range[PrimePi[1000]+1, PrimePi[9999]]], PrimeQ[FromDigits[Rest[Most[IntegerDigits[#]]]]]&] (* Harvey P. Dale, Jan 04 2011 *)


CROSSREFS



KEYWORD

base,nonn


AUTHOR



EXTENSIONS

Corrected and extended by Harvey P. Dale, Jan 04 2011


STATUS

approved



