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.

500, 15500500, 1510001505011550050050015500500

Offset

1,1

Links

Table of n, a(n) for n=1..3.

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

Cf. A002904, A092302.

Sequence in context: A214242 A239046 A279275 * A320206 A320215 A233429

Adjacent sequences: A097422 A097423 A097424 * A097426 A097427 A097428

Keyword

nonn,word,less

Author

Pierre CAMI, Aug 21 2004

Status

approved