18508319domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of (2+1) X (n+1) 0..1 arrays x(i,j) with row sums sum{x(i,j), j=1..n+1} nondecreasing, and column sums sum{i*x(i,j), i=1..2+1} nondecreasing.at n=18A233063Prime numbersat n=1181643