A179221 - OEIS

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

%S 0,2,3,6,8,25,21,24,343,195,486,5929,35568,1450800

%N Iterative mapping: a(1)=0, a(n)=A179216(a(n-1)).

%C a(15) is greater than 10^7 and of the form (p^5)(q^4)rs where p, q, r and s are distinct primes.

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

%Y Cf. A179216, A179222.

%K nonn

%O 1,2

%A _Will Nicholes_, Jul 10 2010