A118098 -id:A118098 - cp's OEIS frontend

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

Jonathan Vos Post, Oct 09 2007

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.

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

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

Cf. A000040, A002963, A105269, A131480.

A002963(a(n)) is in A000040.

A133192 Numbers that require exactly five chisel strokes when written in Roman numerals.

Original entry on oeis.org

8, 13, 14, 16, 19, 21, 41, 53, 54, 56, 59, 61, 91, 103, 104, 106, 109, 111, 151, 201, 400, 502, 505, 510, 550, 600, 1001, 5002, 5005, 5010, 5050, 5100, 10002, 10005, 10010, 10050, 10100, 50002, 50005, 50010, 50050, 50100, 100002, 100005, 100010, 100050, 100100, 500001, 1000000

Offset: 1

Jonathan Vos Post, Oct 09 2007

			Chisel strokes for numerals: I,1; V,2; X,2; L,2; C ( = < ),2; D,3; M,4; 5000 is V with a line over it, 3; 10000 is X with a line over it, 3; 50000 is L with a line over it, 3; 100000 is L with a line over it, 3; 500000 is D with a line over it, 4; 1000000 is M with a line over it, 5. Numerals with two horizontal strokes over them were not common in historical Rome. A002964 has a different evaluation of the strokes of C, as does A118098.

Cf. A002963, A002964, A118098.

Numbers n such that A002963(n) = 5.

cp's OEIS Frontend

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

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

Formula