657152929domain: NPropertiesPrimalityPrimeyesAppears in sequencesPlace a(n) red and b(n) blue balls in an urn; draw 6 balls without replacement; Probability(6 red balls)=Probability(4 red and 2 blue balls); binomial(a(n),6)=binomial(a(n),4)*binomial(b(n),2).at n=19A179123Prime numbersat n=34145889