1053990domain: NAppears in sequencesNumber of excursions of length n with Motzkin-steps avoiding the consecutive steps UU, HH, DU and DD.at n=36A329690a(1) = 8; for n > 1, a(n) is the largest integer m such that m = ((2*x*a(n-1)) / (x+1)) - x, with x a positive nontrivial divisor of m.at n=23A338026