Search: id:A131480 Results 1-1 of 1 results found. %I A131480 %S A131480 2,5,11,59,101,509,1009,1051,3001 %N A131480 Minimal set of prime-strings in Roman numerals. %C A131480 Written in Roman numerals this sequence begins II, V, XI, LIX, CI, DIX, MIX, MLI, MMMI. %C A131480 For a while I actually considered putting in 97 (XCVII) instead of 101 (CI), since XCVII contains CI as a substring. But it also contains II, V and XI as substrings, so going in order strictly from smallest to greatest, 97 must be excluded. %e A131480 a(4) = 59 because it is a prime number and in Roman numerals it's written LIX (all the substrings are composite or not prime: L, LI, LX, I, IX, X). %Y A131480 Cf. A071062, minimal set of prime-strings in base 10. %Y A131480 Sequence in context: A089609 A087185 A127010 this_sequence A018847 A134996 A134998 %Y A131480 Adjacent sequences: A131477 A131478 A131479 this_sequence A131481 A131482 A131483 %K A131480 base,nonn %O A131480 1,1 %A A131480 Robert Happelberg (roberthappelberg(AT)yahoo.com), Jul 27 2007 Search completed in 0.001 seconds