A133194 Numbers requiring a prime number of chisel strokes for their representation in Roman numerals.

2, 3, 4, 5, 6, 8, 9, 10, 11, 13, 14, 16, 18, 19, 21, 23, 24, 26, 29, 31, 38, 41, 43, 44, 46, 49, 50, 51, 53, 54, 56, 58, 59, 61, 63, 64, 66, 69, 71, 78, 83, 84, 86, 88, 89, 91, 93, 94, 96, 99, 100, 101, 103, 104, 106, 108, 109, 111, 113, 114, 116, 119, 121

Offset

1,1

Comments

Finite if one excludes multiple strokes chiseled over the letter, each meaning multiplication by 1000. The subsequence "primes requiring a prime number of chisel strokes for its representation in Roman numerals" begins 2, 3, 5, 11, 13, 19, 23, 29, 31, 41, 43, 53, 59, 61, 71, 83, 89, 101, 103. This sequence uses the definition of strokes given in A002963, not A118098.

Links

Nathaniel Johnston, Table of n, a(n) for n = 1..1215 (complete up to 3999)

Formula

A002963(a(n)) is in A000040.

Example

a(1) = 2 because II requires 2 strokes (neglecting serifs).
a(44) = 88 because LXXXVIII requires 13 strokes.

Crossrefs

Cf. A000040, A002963, A105269, A131480.

Sequence in context: A353202 A068398 A293168 * A177989 A022774 A153134

Adjacent sequences: A133191 A133192 A133193 * A133195 A133196 A133197

Keyword

base,easy,nonn

Author

Jonathan Vos Post, Oct 09 2007

Status

approved