A195602 Primes written with prime number of Roman numerals.

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

Links

Table of n, a(n) for n=1..60.

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

Cf. A003587, A195526.

Sequence in context: A092940 A045326 A214029 * A105897 A129386 A278699

Adjacent sequences: A195599 A195600 A195601 * A195603 A195604 A195605

Keyword

nonn,base

Author

Juri-Stepan Gerasimov, Sep 21 2011

Status

approved