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A062726
Numbers that do not contain repeated letters when written in Roman numerals.
1
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
1,2
EXAMPLE
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
CROSSREFS
Cf. A006968.
Sequence in context: A177103 A114454 A008854 * A159629 A328173 A223138
KEYWORD
nonn,base,fini,full
AUTHOR
Rodolfo Kurchan, Jul 11 2001
EXTENSIONS
Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jul 23 2001
STATUS
approved