OFFSET
1,1
COMMENTS
This sequence is complete up to 3999.
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
KEYWORD
nonn,easy
AUTHOR
Claudio Meller, May 25 2009
EXTENSIONS
a(8) from Nathaniel Johnston, May 18 2011
STATUS
approved