0,2

P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 2000, p. 156.

G.f.: (1+x+4*x^2+11*x^3+8*x^4+21*x^5+6*x^6+9*x^7+x^8)/((1-x)^4*(1+x+x^2)*(1+x^2)).

Sequence in context: A062858 A095735 A020875 this_sequence A002842 A051041 A002906

Adjacent sequences: A063807 A063808 A063809 this_sequence A063811 A063812 A063813

nonn

njas, Aug 20 2001