1,2

a(2) = IV (first usage of V);

a(4) = XL (first usage of L).

Cf., A123457.

Sequence in context: A055872 A066924 A101529 this_sequence A073414 A085110 A013459

Adjacent sequences: A118636 A118637 A118638 this_sequence A118640 A118641 A118642

easy,nonn

Greg Huber (huber(AT)alum.mit.edu), May 09 2006