The sequence of numbers obtained by letting , and defining
where
is the least prime factor. The first few terms
are 2, 3, 7, 43, 13, 53, 5, 6221671, 38709183810571, 139, ... (OEIS A000945).
Only 43 terms of the sequence are known; the 44th requires factoring a composite
180-digit number.
Guy, R. K. and Nowakowski, R. "Discovering Primes with Euclid." Delta (Waukesha)5, 49-63, 1975.Mullin,
A. A. "Recursive Function Theory." Bull. Amer. Math. Soc.69,
737, 1963.Naur, T. "Mullin's Sequence of Primes Is Not Monotonic."
Proc. Amer. Math. Soc.90, 43-44, 1984.Sloane, N. J. A.
Sequence A000945/M0863 in "The On-Line
Encyclopedia of Integer Sequences."Wagstaff, S. S. "Computing
Euclid's Primes." Bull. Institute Combin. Applications8, 23-32,
1993.
, and defining
is the least prime factor. The first few terms
are 2, 3, 7, 43, 13, 53, 5, 6221671, 38709183810571, 139, ... (OEIS A000945).
Only 43 terms of the sequence are known; the 44th requires factoring a composite
180-digit number.
