1704377domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of 4 X n 0..1 arrays with rows unimodal and columns nondecreasing.at n=18A225011a(n) = Sum_{k=0..n} (-1)^k * binomial(3*n-k+3,n-k).at n=8A390588Prime numbersat n=128443