468692890308domain: NAppears in sequencesNumber of Delannoy paths of length n with no (1,1)-steps on the line y=x.at n=17A109980G.f.: ((1+2*x)*sqrt(1-6*x^2+x^4)-1+5*x^2-2*x^3)/(2*x*(1-6*x^2)).at n=34A212205