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A195602
Primes written with prime number of Roman numerals.
0
2, 3, 7, 11, 19, 23, 41, 43, 47, 59, 61, 67, 79, 83, 97, 101, 109, 113, 131, 137, 149, 151, 157, 173, 199, 223, 227, 239, 241, 263, 281, 293, 311, 313, 317, 331, 349, 353, 401, 419, 421, 439, 443, 461, 463, 467, 479, 491, 509, 557, 569, 571, 577, 599, 601, 607, 619, 641, 643, 647
OFFSET
1,1
MATHEMATICA
Select[Prime[Range[200]], PrimeQ[Length[Characters[IntegerString[#, "Roman"]]]]&] (* Harvey P. Dale, Mar 19 2013 *)
PROG
(PARI) Roman(n)=my(s); while(n, s+=[0, 1, 2, 3, 2, 1, 2, 3, 4, 2][n%10+1]; n\=10); s
forprime(p=2, 3999, if(isprime(Roman(p)), print1(p", "))) \\ Charles R Greathouse IV, Oct 06 2011
CROSSREFS
Sequence in context: A092940 A045326 A214029 * A105897 A129386 A278699
KEYWORD
nonn,base
AUTHOR
STATUS
approved