486890domain: NAppears in sequencesNumber of Dyck n-paths with ascents and descents of length equal to 1 (mod 4).at n=27A023427G.f. satisfies: A(x) = (1 + x*A(x)) * (1 + x^4*A(x)).at n=26A216116Expansion of Product_{k>=1} ((1 + x^(2*k-1)) / (1 - x^(2*k-1)))^(2*k-1).at n=25A292038