

A160754


Numbers k such that k, 2k, 3k and 4k use the same number of characters when expressed in Roman numerals.


0




OFFSET

1,1


COMMENTS

This sequence is complete up to 3999.


LINKS

Table of n, a(n) for n=1..8.


EXAMPLE

1*36 = 36 = XXXVI,
2*36 = 72 = LXXII,
3*36 = 108 = CVIII,
4*36 = 144 = CXLIV,
so 36 is a term;
1*153 = 153 = CLIII,
2*153 = 306 = CCCVI,
3*153 = 459 = CDLIX,
4*153 = 612 = DCXII,
so 153 is a term.


MAPLE

for n from 1 to 3999 do if(length(convert(n, roman)) = length(convert(2*n, roman)) and length(convert(n, roman)) = length(convert(3*n, roman)) and length(convert(n, roman)) = length(convert(4*n, roman)))then printf("%d, ", n): fi: od: # Nathaniel Johnston, May 18 2011


CROSSREFS

See A006968 for the basic underlying sequence.
Sequence in context: A039495 A263120 A034592 * A275496 A117511 A250632
Adjacent sequences: A160751 A160752 A160753 * A160755 A160756 A160757


KEYWORD

nonn,easy


AUTHOR

Claudio Meller, May 25 2009


EXTENSIONS

a(8) from Nathaniel Johnston, May 18 2011


STATUS

approved



