A002964 Smallest number requiring n chisel strokes for its representation in Roman numerals.

1, 2, 3, 7, 8, 17, 18, 27, 28, 37, 38, 87, 88, 187, 188, 287, 288, 387, 388, 788, 887, 888, 1388, 1788, 1887, 1888, 2388, 2788, 2887, 2888, 3388, 3788, 3887, 3888

Offset: 1

Author

N. J. A. Sloane

Keywords

• base
• nonn
• nice

Comments

A002963(a(n)) = n. - Reinhard Zumkeller, Apr 14 2013

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Roman Numerals
• Wikipedia, Roman numerals

Crossrefs

Cf. A002963.

Programs

Haskell

a002964 = (+ 1) . fromJust . (`elemIndex` (map a002963 [1..3888]))
-- Reinhard Zumkeller, Apr 14 2013

Mathematica

DeleteDuplicates[Table[{n,Total[Characters[RomanNumeral[n]]/.{"L"->2,"X"->2,"V"->2,"I"->1,"M"->4,"C"->2,"D"->3}]},{n,4000}],GreaterEqual[#1[[2]],#2[[2]]]&][[;;,1]] (* Harvey P. Dale, Jan 19 2025 *)

Extensions

More terms from Erich Friedman

For n>13: data corrected and completed up to A002963(3888)=34 by Reinhard Zumkeller, Apr 14 2013