[seqfan] Ratio of Chisel Strokes in English names and Roman numerals

Jonathan Post jvospost3 at gmail.com
Mon Sep 7 16:31:14 CEST 2009


Taking the 16 positive integers (A163670) which are entirely written
with straight line segments, then there is a subset of 5 of them for
which the number of chisel strokes of the Roman numeral representation
(a007963) divides the number of chisel strokes of the English name.

I'm not sure if there's a good seq here, but it helps with my High
School Math teaching, in clairifying the distinction between number
and prepresentaion, while practicing counting, Roman Numerals, and
division.

n  a(n) Name(a(n))  Strokes(name(a(n))) Roman(a(n))  Strokes(Roman(n))
 Strokes(English)/Strokes/Roman
1   5    FIVE          10                           V
2                           10/2 = 5
2   9    NINE          11                           IX                  3
3   10  TEN             9                           X                   2
4   11  ELEVEN     19                          XI                   3
5   12 TWELVE      18                         XII                   4
6   15  FIFTEEN     20                         XV                  4
                        20/4 = 5
7   19  NINETEEN  24                         XIX                  5
8   20  TWENTY     18                         XX                  4
9   25  TWENTYFIVE  30                    XXV                 6
                   30/6 = 5
10 29  TWENTYNINE  31                    XXIX                 7
11 50  FIFTY           12                       L
2                           12/2 = 6
12 55  FIFTYFIVE    22                       LV                   4
13 59  FIFTYNINE    23                       LIX                  5
14 90  NINETY         16                       XC [X<)           4
                       16/4 = 4
15 95  NINETYFIVE  26                       XCV               6
16 99  NINETYNINE  27                      XCIX               7

I am not happy with the difference in the way that curves are treated
in English count and Roman numeral count (i.e. C as two chisel strokes
in the Roman numeral per A007963) versus the more recent distinction
between segment, semicicircle, circle, and S-curve.

Any suggestions?

Happy Labor Day,

Jonathan Vos Post




More information about the SeqFan mailing list