A131480 Minimal set of prime-strings in Roman numerals.

2, 5, 11, 59, 101, 509, 1009, 1051, 3001

Offset: 1

Author

Robert Happelberg (roberthappelberg(AT)yahoo.com), Jul 27 2007

Keywords

• base
• nonn

Comments

Written in Roman numerals this sequence begins II, V, XI, LIX, CI, DIX, MIX, MLI, MMMI.

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.

Examples

			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).
		

Crossrefs

Cf. A071062, minimal set of prime-strings in base 10.