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 A077801 #12 Apr 11 2024 04:09:01
%S A077801 38,54,87,95,114,126,135,147,174,182,209,215,216,222,258,266,285,294,
%T A077801 297,315,342,378,430,447,455,456,494,518,540,546,551,609,627,632,635,
%U A077801 645,654,665,702,762,783,798,836,894,899,945,957,1015,1022,1032,1064
%N A077801 Non-balanced numbers in A015767.
%H A077801 Amiram Eldar, <a href="/A077801/b077801.txt">Table of n, a(n) for n = 1..10000</a>
%F A077801 sigma_9(a(n)) mod phi(a(n)) = 0; sigma(a(n)) mod phi(a(n)) <> 0.
%t A077801 q[n_] := Sign[Mod[DivisorSigma[{1, 9}, n], EulerPhi[n]]] == {1, 0}; Select[Range[1000], q] (* _Amiram Eldar_, Apr 11 2024 *)
%o A077801 (PARI) is(n) = {my(f = factor(n), phi = eulerphi(f)); (sigma(f) % phi) && !(sigma(f, 9) % phi);} \\ _Amiram Eldar_, Apr 11 2024
%Y A077801 Cf. A000010, A000203, A013957, A015767, A020492, A078539.
%Y A077801 Cf. A074866, A074868, A077803, A078544, A078549, A078550.
%K A077801 nonn
%O A077801 1,1
%A A077801 _Labos Elemer_, Dec 05 2002