189407domain: NPropertiesPrimalityPrimeyesAppears in sequencess(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (composite numbers), t = (F(2), F(3), ...).at n=19A024589a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (composite numbers), t = (F(2), F(3), F(4), ...).at n=18A025103Prime numbersat n=17115