0,2

Roland Bacher, Apr 08 2008, Table of n, a(n) for n = 0..14

R. Bacher, The special subgroup of invertible non-commutative rational power series as a metric group, arXiv:0804.1092

The reference contains a somewhat complicated formula.

Sequence in context: A051753 A323996 A094073 * A152793 A042769 A091792

Adjacent sequences: A137339 A137340 A137341 * A137343 A137344 A137345

nonn

Roland Bacher, Apr 08 2008

approved