A179222 - OEIS

%I #2 Mar 31 2012 14:41:48

%S 1,4,9,7,10,12,14,11,27,17,125,208,4489,42588

%N Iterative mapping: a(1)=1, a(n)=A179216(a(n-1)).

%C a(15) is greater than 10^7 and of the form (p^5)(q^5)(r^2) where p, q and r are distinct primes.

%H Will Nicholes, <a href="http://willnicholes.com/math/primesigmap.htm">Iterative mapping of prime signatures</a>.

%Y Cf. A179216, A179221.

%K nonn

%O 1,2

%A _Will Nicholes_, Jul 10 2010