437977domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(n) is the smallest odd prime p such that 2^n*p has n digits but has at most two distinct digits; or 0 if no such prime exists.at n=8A124244Indices of tetrahedral numbers that are Fermat pseudoprimes to base 2.at n=15A321866Prime numbersat n=36791