Pensieve header: A Drinfel’d associator Φ to degree 8.

Get["http://drorbn.net/AcademicPensieve/Projects/WKO4/FreeLie.m"];
Φs[2,1]=Φs[3,1]=Φs[3,2]=0;Φs[3,1,2]=1/24; Φ=DKS[3, Φs];
SeriesSolve[Φ, (Φ^(σ[3,2,1]))≡-Φ ∧ Φ**(Φ^(σ[1,23,4]))**(Φ^(σ[2,3,4]))≡(Φ^(σ[12,3,4]))**(Φ^(σ[1,2,34]))];
Φ@{6}

Timing[Φ@{8}]

(A computation  to degree 10 is available at http://drorbn.net/AcademicPensieve/Projects/WKO4/nb/Phi.pdf. It takes about 8 hours and prints on about 6 pages).