[seqfan] More terms for A195265 and A230305 ?

Neil Sloane njasloane at gmail.com
Sun Oct 27 07:56:42 CET 2013

Dear Seqfans, A195265 was created in 2011, but presumably we have better
factoring algorithms now and more computers and
more people and a bigger cloud.

The definition is simple - start with 20 and keep
applying the map  x -> A080670(x) until you reach a prime;
A195264(20) will be the prime that is reached (or -1 if
no prime is ever reached).

A230305(n) is the number of steps to reach a prime,
starting with n (or -1 if no prime is ever reached).
The question then is, what is A230305(20)?

Could someone extend A195265 and see what happens? (it could also use a
b-file). It /should/ reach a prime sooner or later!


Dear Friends, I have now retired from AT&T. New coordinates:

Neil J. A. Sloane, President, OEIS Foundation
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com

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