202637domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes that remain prime through 5 iterations of the function f(x) = 9x + 4.at n=15A023353a(1) = 2, a(2n) = smallest prime of the form k*a(2n-1) -1, k >1, a(2n+1) = smallest prime of the form r*a(2n)+1, r >1.at n=9A085872Prime numbersat n=18195