398863domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(n) = Sum{T(i,j)}, 0<=j<=i, 0<=i<=n, T given by A026907.at n=12A026917a(n) = 6*binomial(n,4) + 6*binomial(n,3) + 4*binomial(n,2) + 2*n + 1.at n=36A385689Prime numbersat n=33770