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 A335288 #12 Jun 03 2020 05:28:16 %S A335288 1,2,3,6,14,15,30,35,42,44,60,70,78,105,126,132,190,210,220,312,357, %T A335288 418,558,570,660,693,714,728,910,1045,1254,1386,1395,1428,1540,2090, %U A335288 2108,2184,2730,2790,3135,3465,3640,3692,3762,4522,4620,4674,5236,5278,6270 %N A335288 Unitary balanced numbers: numbers k such that uphi(k) (A047994) divides usigma(k) (A034448). %C A335288 Terms that are also balanced numbers (A020492) include the squarefree balanced numbers (A078557). The nonsquarefree common terms are in A335289. %H A335288 Amiram Eldar, <a href="/A335288/b335288.txt">Table of n, a(n) for n = 1..10000</a> %e A335288 6 is a term since usigma(6) = 12 is divisible by uphi(6) = 2. %t A335288 f[1, 1] = 1; f[p_, e_]:= (p^e + 1)/(p^e -1); ubalQ[n_] := IntegerQ[Times @@ (f @@@ FactorInteger[n])]; Select[Range[10^4], ubalQ] %Y A335288 The unitary version of A020492. %Y A335288 A078557 is a subsequence. %Y A335288 Cf. A034448, A047994, A335289. %K A335288 nonn %O A335288 1,2 %A A335288 _Amiram Eldar_, May 30 2020