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 A342106 #13 Mar 08 2021 22:53:13
%S A342106 4,8,9,10,16,18,24,25,26,28,32,34,36,40,48,50,52,58,63,64,72,74,75,76,
%T A342106 80,81,82,84,88,90,98,100,104,106,108,112,117,120,121,122,124,128,130,
%U A342106 136,144,146,148,152,156,160,162,170,171,172,175,176,178,180,192,194,196,200
%N A342106 Numbers that are not arithmetic and not balanced.
%C A342106 Equivalently, numbers m such that neither tau(m) (A000005) nor phi(m) (A000010) divide sigma(m) (A000203).
%C A342106 A342103, A342104, A342105 and this sequence form a partition of the set of positive integers N* (A000027).
%C A342106 There are no primes in the sequence since 2 is in A342104, 3 is in A342103, and odd primes >= 5 are in A342105.
%e A342106 Sigma(9) = 13, tau(9) = 3 and phi(9) = 6, hence sigma(9)/tau(9) = 13/3 and sigma(9)/phi(9) = 13/6, 9 is a term.
%p A342106 with(numtheory): filter:= q -> (sigma(q) mod phi(q) <> 0) and (sigma(q) mod tau(q) <> 0) : select(filter, [$1..200]);
%t A342106 Select[Range[200], ! Or @@ Divisible[DivisorSigma[1, #], {DivisorSigma[0, #], EulerPhi[#]}] &] (* _Amiram Eldar_, Mar 08 2021 *)
%o A342106 (PARI) isok(m) = my(s=sigma(m)); (s % numdiv(m)) && (s % eulerphi(m)); \\ _Michel Marcus_, Mar 08 2021
%Y A342106 Cf. A000005 (tau), A000010 (phi), A000203 (sigma).
%Y A342106 Cf. A020492, A003601.
%Y A342106 Cf. A342103, A342104, A342105.
%K A342106 nonn
%O A342106 1,1
%A A342106 _Bernard Schott_, Mar 08 2021