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 A286266 #18 Mar 26 2023 02:19:50
%S A286266 2,36,383,3708,35731,347505,3407290,33579303,332026623,3290205509
%N A286266 Number of totient abundant numbers <= 10^n.
%C A286266 Totient abundant numbers are defined in A286265.
%C A286266 a(3)-a(8) were calculated by Loomis & Luca (2008).
%H A286266 Paul Loomis and Florian Luca, <a href="https://www.emis.de/journals/INTEGERS/papers/i6/i6.Abstract.html">On totient abundant numbers</a>, Electronic Journal of Combinatorial Number Theory, Vol. 8, #A06 (2008).
%e A286266 There are 2 totient abundant numbers <= 10^1 (5 and 7), thus a(1)=2.
%t A286266 Accumulate@ Table[Count[Select[Range[10^(n - 1) + 1, 10^n], (Total@ FixedPointList[EulerPhi, #] - (# + 1)) > # &], k_ /; k <= 10^n], {n, 6}] (* _Michael De Vlieger_, May 06 2017, after _Alonso del Arte_ at A092693 *)
%o A286266 (PARI) s(n) = {n=eulerphi(n); if(n==1, 1, n+s(n));}
%o A286266 lista(nmax) = {my(c = 0, r = 10); for(k = 1, 10^nmax, if(s(k) > k, c++); if(k == r, print1(c, ", "); r *= 10));} \\ _Amiram Eldar_, Mar 26 2023
%Y A286266 Cf. A000010, A082897, A092693, A286265.
%K A286266 nonn,more
%O A286266 1,1
%A A286266 _Amiram Eldar_, May 05 2017
%E A286266 a(9)-a(10) from _Amiram Eldar_, Mar 26 2023