156206233domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(n) = Sum_{k=0..floor(n/3)} (binomial(n+1, k)*binomial(2*n-3*k, n-3*k)/(n+1)).at n=16A071969Duplicate of A071969.at n=16A119255Prime numbersat n=8773610