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 A374784 #8 Jul 20 2024 14:41:19
%S A374784 1,4,6,8,10,24,14,16,18,8,22,16,26,56,60,32,34,72,38,80,4,88,46,96,50,
%T A374784 104,54,112,58,48,62,64,132,136,28,16,74,152,52,160,82,16,86,176,180,
%U A374784 184,94,64,98,40,204,208,106,216,20,224,76,232,118,160,122,248
%N A374784 Denominator of the mean unitary abundancy index of the unitary divisors of n.
%H A374784 Amiram Eldar, <a href="/A374784/b374784.txt">Table of n, a(n) for n = 1..10000</a>
%e A374784 For n = 4, 4 has 2 unitary divisors, 1 and 4. Their unitary abundancy indices are usigma(1)/1 = 1 and usigma(4)/4 = 5/4, and their mean unitary abundancy index is (1 + 5/4)/2 = 9/8. Therefore a(4) = denominator(9/8) = 8.
%t A374784 f[p_, e_] := 1 + 1/(2*p^e); a[1] = 1; a[n_] := Denominator[Times @@ f @@@ FactorInteger[n]]; Array[a, 100]
%o A374784 (PARI) a(n) = {my(f = factor(n)); denominator(prod(i = 1, #f~, 1 + 1/(2*f[i,1]^f[i,2])));}
%Y A374784 Cf. A034444, A034448 (usigma), A077610, A374783 (numerators).
%Y A374784 Similar sequences: A374777/A374778, A374786/A374787.
%K A374784 nonn,easy,frac
%O A374784 1,2
%A A374784 _Amiram Eldar_, Jul 20 2024