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A160754 Numbers k such that k, 2k, 3k and 4k use the same number of characters when expressed in Roman numerals. 0
36, 153, 315, 351, 360, 448, 736, 1386 (list; graph; refs; listen; history; text; internal format)
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

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Last modified May 17 04:24 EDT 2022. Contains 353728 sequences. (Running on oeis4.)