270349domain: NAppears in sequencesa(n) = T(n,n), array T given by A048494.at n=12A048504Golden semiprimes: a(n)=p*q and abs(p*phi-q)<1, where phi = golden ratio = (1+sqrt(5))/2.at n=32A108540a(n) = Sum_{k=0..floor(n/3)} binomial(n+k-1,k) * binomial(n+k-1,n-3*k).at n=12A389377