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 A234958 #10 Jan 15 2025 01:44:24
%S A234958 0,4,19,103,422,1559,5645,19329,64040,207637,663845,2103055
%N A234958 Number of composite k-Lehmer numbers up to 10^n.
%C A234958 A number n is a k-Lehmer number if there exist a k such that phi(n) divides (n-1)^k.
%C A234958 The values of a(10) and a(11) computed by N. McNew in the linked paper are smaller than mine. I provide a link to my full list so that it could be independently checked.
%H A234958 José María Grau and Antonio M. Oller-Marcén, <a href="http://arxiv.org/abs/1012.2337">On k-Lehmer numbers</a>, arXiv:1012.2337 [math.NT], 2010-2012; Integers, 12(2012), #A37.
%H A234958 Nathan McNew, <a href="http://arxiv.org/abs/1210.2001">Radically weakening the Lehmer and Carmichael conditions</a>, arXiv:1210.2001 [math.NT], 2012; International Journal of Number Theory 9 (2013), 1215-1224.
%H A234958 Giovanni Resta, <a href="http://www.numbersaplenty.com/set/Lehmer_number/">k-Lehmer numbers</a> composite k-Lehmer numbers up to 10^12.
%e A234958 There are 4 k-Lehmer numbers up to 10^2, namely 15, 51, 85, and 91, so a(2) = 4.
%t A234958 kLQ[n_] := n > 1 && ! PrimeQ[n] && Mod[n-1, Times @@ First /@ FactorInteger@ EulerPhi@n] == 0; Table[Length@ Select[Range[2, 10^k], kLQ], {k, 6}]
%Y A234958 Cf. A187731, A173703, A234936.
%K A234958 nonn,more
%O A234958 1,2
%A A234958 _Giovanni Resta_, Jan 01 2014