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 A238227 #25 Jul 23 2019 07:49:21 %S A238227 1,56,66,70,992,1012,2260,2516,6042,6902,7192,7210,7232,7750,7912, %T A238227 8178,9086,10792,12198,13706,17272,30592,32778,33352,35032,40166, %U A238227 44034,45010,46670,47710,55374,62296,63688,65570,114256,132916,133892,138244,141236,146804,155572 %N A238227 Numbers n such that if x=sigma(n)-tau(n)-n then n=sigma(x)-tau(x)-x. %C A238227 If the second term (4) is not considered, A056075 is almost a subset of this sequence: it lists the fixed points of the transform n -> sigma(n)-tau(n)-n. %H A238227 Amiram Eldar, <a href="/A238227/b238227.txt">Table of n, a(n) for n = 1..1001</a> (terms 1..50 from Paolo P. Lava) %e A238227 Fixed points: 56, 7192, 7232, 7912, 10792, ... %e A238227 sigma(66) = 144, tau(66) = 8 and 144 - 8 - 66 = 70. %e A238227 sigma(70) = 144, tau(70) = 8 and 144 - 8 - 70 = 66. %p A238227 with(numtheory); P:=proc(q)local a,n; %p A238227 for n from 1 to q do a:=sigma(n)-tau(n)-n; %p A238227 if sigma(a)-tau(a)-a=n then print(n); %p A238227 fi; od; end: P(10^6); %Y A238227 Cf. A000005, A000203, A056075, A238225, A238226, A238228, A238229, A238230. %K A238227 nonn %O A238227 1,2 %A A238227 _Paolo P. Lava_, Feb 20 2014