A118098 Numbers that require three strokes when written in Roman numerals (excluding serifs). III IV VI IX XI LI XC CII CV CX CL.

3, 4, 6, 9, 11, 51, 90, 102, 105, 110, 150, 201, 300, 400, 501, 600

Offset: 1

Author

Dylan Nicholson (wizofaus(AT)hotmail.com), May 11 2006

Keywords

• nonn
• easy
• fini
• full
• base

Comments

Unlike the case in A002963, C is counted as one stroke and D is counted as two strokes here. This sequence is complete up to 3999, though it may contain some more terms such as 5000 depending on the convention used to represent larger numbers. - Nathaniel Johnston, May 18 2011

Formula

Numbers that require three strokes when written in Roman numerals (excluding serifs).

Extensions

a(12)-a(16) from Nathaniel Johnston, May 18 2011