564928domain: NAppears in sequencesNumber of 1:2:sqrt(5) proportioned triangles on an (n+1) X (n+1) grid.at n=34A190099Expansion of x/(1-8*x-12*x^2).at n=7A239549a(n) = Sum_{k=0..n} binomial(k, 8*(n-k)).at n=24A306752a(n) = Sum_{k=0..floor(n/2)} binomial(k,4*n-8*k).at n=48A390220