29865749domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(n) = A322237(n) / (n*(n+1)/2), where A322237(n) = [x^(n-1)] Product_{k=1..n} (k + x + k*x^2), for n >= 1.at n=9A322236Prime numbersat n=1849973