A036787 - OEIS

A036787

Length of Roman notation for n = length of decimal representation.

1, 5, 11, 15, 20, 40, 51, 55, 60, 90, 102, 104, 106, 109, 111, 115, 120, 140, 151, 155, 160, 190, 201, 205, 210, 250, 300, 401, 405, 410, 450, 502, 504, 506, 509, 511, 515, 520, 540, 551, 555, 560, 590, 601, 605, 610, 650, 700, 901, 905, 910, 950, 1003, 1007

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Nathaniel Johnston, Table of n, a(n) for n = 1..144 (complete up to 3999)

FORMULA

A006968(a(n)) = A055642(a(n)). - Reinhard Zumkeller, Apr 20 2013

EXAMPLE

15 = XV has length 2 in both notations.

MAPLE

for n from 1 to 3999 do if(length(convert(n, roman)) = length(n))then printf("%d, ", n): fi: od: # Nathaniel Johnston, May 18 2011

MATHEMATICA