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 A362550 #43 Apr 29 2023 00:26:31 %S A362550 0,13,210,2627,29747,319817,3365629,34962092,360152096,3688820638 %N A362550 Number of even nontotients less than 10^n. %e A362550 a(1) = 0 since 2, 4, 6, and 8 are terms of A002202. %e A362550 a(2) = 13 since there are 13 even nontotients less than 100, and they are 14,26,34,38,50,62,68,74,76,86,90,94 and 98. %o A362550 (PARI) a(n)=sum(k=1,10^n\2, !istotient(2*k)) \\ _Charles R Greathouse IV_, Apr 25 2023 %Y A362550 Cf. A002202, A005277, A072077. %K A362550 nonn,more %O A362550 1,2 %A A362550 _Robert G. Wilson v_, Apr 24 2023 %E A362550 a(8)-a(10) from _Charles R Greathouse IV_, Apr 25 2023