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A097425
a(1) = 500, then a(n) is the concatenation of the roman numerals (I, V, X, L, C, D, M) visible in a(n-1) written in English.
0
500, 15500500, 1510001505011550050050015500500
OFFSET
1,1
EXAMPLE
a(1) = 500, which is fIVe hunDreD, so a(2) = concat(1, 5, 500, 500) = 15500500, which is fIVeteen MILLIon fIVe hunDreD thousanD fIVe hunDreD, so a(3) = concat(1, 5, 1000, 1, 50, 50, 1, 1, 5, 500, 500, 500, 1, 5, 500, 500), etc.
CROSSREFS
Sequence in context: A214242 A239046 A279275 * A320206 A320215 A233429
KEYWORD
nonn,word,less
AUTHOR
Pierre CAMI, Aug 21 2004
STATUS
approved