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 A308945 #17 Jul 12 2019 20:18:08 %S A308945 2,20,213,2152,21594,216009,2159776,21595522,215951111,2159507603, %T A308945 21595061256,215950604593 %N A308945 Number of totient numbers, phi(k), k <= 10^n, whose initial digit is 1. %C A308945 The probability that a totient number starts with an initial 1 does not obey Benford's law however it does appear to tend to a constant value. In a sample of 10^9 totient numbers the distribution of initial digits 1 - 9 is approx. 21.595%, 20.774%, 16.457%, 12.682%, 7.904%, 6.633%, 5.505%, 4.634%, 3.816%. %H A308945 Wikipedia, <a href="https://en.wikipedia.org/wiki/Benford%27s_law">Benford's law</a> %e A308945 a(1)=2 as the first 10 totient numbers are {1, 1, 2, 2, 4, 2, 6, 4, 6, 4} and the occurrence of numbers with an initial 1 is 2. %t A308945 lst1={}; Do[lst=Table[0, {n, 1, 9}]; Do[++lst[[First@IntegerDigits@EulerPhi[n]]], {n, 1, 10^m}]; AppendTo[lst1, lst[[1]]], {m, 1, 7}]; lst1 %o A308945 (PARI) a(n) = {k=0; for(j=1, 10^n, if(digits(eulerphi(j))[1]==1, k++)); k} \\ _Jinyuan Wang_, Jul 04 2019 %Y A308945 Cf. A000010, A047855, A073517, A073557. %K A308945 nonn,base,more %O A308945 1,1 %A A308945 _Frank M Jackson_, Jul 02 2019 %E A308945 a(10)-a(12) from _Giovanni Resta_, Jul 04 2019