%I #6 Sep 23 2019 18:07:04
%S 1,5,10,41,19,18,73,293,43,173,24,97,389,179,242,39,157,54,38,23,34,
%T 137,67,269,362,36,34
%N a(n+1)=sopfr(4a(n)+1), with sopfr=A001414. Finishes with the cycle (34, 137, 67, 269, 362, 36).
%C In the class of recurrence sequences a(n+1)=sopfr(C*a(n)+D), with C=4, D=1. It is a simple example where it finishes with a nontrivial cycle.
%F a(n+1) = A001414(4*a(n)+1).
%t sopfr = Function[x, Plus @@ Map[Times @@ # &, FactorInteger[x]]]; NestList[sopfr[4# + 1] &, 1, 40]
%t NestList[Total[Times@@@FactorInteger[4*#+1]]&,1,30] (* _Harvey P. Dale_, Sep 23 2019 *)
%Y Cf. A136136, A136137.
%K fini,nonn
%O 0,2
%A _Carlos Alves_, Dec 16 2007