A062726 Numbers that do not contain repeated letters when written in Roman numerals.

1, 4, 5, 6, 9, 10, 11, 14, 15, 16, 40, 41, 44, 45, 46, 50, 51, 54, 55, 56, 59, 60, 61, 64, 65, 66, 90, 91, 94, 95, 96, 100, 101, 104, 105, 106, 109, 110, 111, 114, 115, 116, 140, 141, 144, 145, 146, 150, 151, 154, 155, 156, 159, 160, 161, 164, 165, 166, 400, 401, 404

Offset: 1

Author

Rodolfo Kurchan, Jul 11 2001

Keywords

• nonn
• base
• fini
• full

Examples

			9 is OK because when written in Roman numerals it is IX and has no letter repeated.
The largest possible term is a(316) = 1666 = MDCLXVI. - _Sean A. Irvine_, Apr 07 2023
		

Links

• Sean A. Irvine, Table of n, a(n) for n = 1..316
• P. Lewis, Roman numerals and calendar

Crossrefs

Cf. A006968.

Extensions

Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jul 23 2001