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 A323331 #7 Jan 11 2019 04:23:32 %S A323331 11398670,22797340,38369450,45594680,56993350,59334310,76738900, %T A323331 91189360,113986700,118668620,153477800,182378720,209524210,227973400, %U A323331 237337240,268586150,284966750,306955600,364757440,419048420,455946800,474674480,537172300,539867650,569933500 %N A323331 Smallest member of sociable quadruples using Dedekind psi function (A001615). %C A323331 Numbers k whose iterations of k -> A001615(k) - k are cyclic with a period of 4, and in each cyclic quadruple k is the least of the 4 members. %e A323331 11398670 is in the sequence since the iterations of k -> A001615(k) - k are cyclic with a period of 4: 11398670, 11475730, 12474350, 14093650, 11398670, ... and 11398670 is the smallest member of the quadruple. %t A323331 t[0]=0; t[1]=0; t[n_]:=(Times@@(1+1/Transpose[FactorInteger[n]][[1]])-1)*n; %t A323331 seq[n_]:=NestList [t, n, 4][[2;; 5]] ; aQ[n_] := Module[ {s=seq[n]}, n==Min[s] && Count[s, n]==1]; s={}; Do[If[aQ[n], AppendTo[s, n]], {n, 1, 10^9}]; s %Y A323331 Cf. A001615, A090615, A319902, A319915, A323327, A323328, A323329, A323330. %K A323331 nonn %O A323331 1,1 %A A323331 _Amiram Eldar_, Jan 11 2019