This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A098187 #8 Oct 15 2013 22:32:34
%S A098187 81570,114270,137046,169998,177906,182082,182094,185190,194574,194586,
%T A098187 201642,203442,204420,204540,212466,212874,213870,219306,219318,
%U A098187 230874,231438,231834,231846,232626,237678,238134,242634,258882,259338,259350
%N A098187 Initial seeds x which will enter a cycle of length 4 under the iteration of x -> A063919(x), the sum of proper unitary divisors.
%C A098187 The sequence is the attractor-basin of set of {C4} cycles belonging to this iteration.
%C A098187 The {C4} attractor-set is displayed separately in A098188.
%e A098187 81570 is in the sequence because its track under the iterated map is 81570, 114270, 182082, 182094, 232626, 237678, 305682, 352878, 360978, 403662, 420738, [420750, 395730, 395910, 420570], 420750.., where the cycle is indicated by brackets. The 4 recurrent terms appear after 11 transients for this case.
%Y A098187 Cf. A098185, A098186, A002827, A097024, A097030.
%K A098187 nonn
%O A098187 1,1
%A A098187 _Labos Elemer_, Sep 02 2004