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 A383056 #7 Apr 15 2025 10:26:19
%S A383056 1,2,1,2,1,4,4,4,4,1,2,4,4,2,4,4,4,1,2,4,1,4,4,1,2,4,4,2,1,8,8,8,8,8,
%T A383056 8,8,8,8,8,8,8,1,2,4,1,4,4,1,2,4,1,4,4,1,4,2,4,1,2,8,8,8,8,8,8,2,1,4,
%U A383056 2,8,8,8,8,8,8,8,8,1,2,4,4,2,1,8,8,8,8,8
%N A383056 Denominators of the partial sums of the reciprocals of the number of unitary divisors function (A034444).
%D A383056 Jean-Marie De Koninck and Aleksandar Ivić, Topics in Arithmetical Functions, North-Holland Publishing Company, Amsterdam, Netherlands, 1980. See pp. 42-43.
%D A383056 Steven R. Finch, Mathematical Constants II, Cambridge University Press, 2018, p. 50.
%H A383056 Amiram Eldar, <a href="/A383056/b383056.txt">Table of n, a(n) for n = 1..10000</a>
%H A383056 Jean-Marie De Koninck and Jacques Grah, <a href="http://doi.org/10.4064/cm-79-2-249-272">Arithmetic functions and weighted averages</a>, Colloquium Mathematicum, Vol. 79. No. 2 (1999), pp. 249-272.
%F A383056 a(n) = denominator(Sum_{k=1..n} 1/A034444(k)).
%e A383056 Fractions begin with 1, 3/2, 2, 5/2, 3, 13/4, 15/4, 17/4, 19/4, 5, 11/2, 23/4, ...
%t A383056 Denominator[Accumulate[1/Array[2^PrimeNu[#] &, 100]]]
%o A383056 (PARI) list(nmax) = {my(s = 0); for(k = 1, nmax, s += 1 / 2^omega(k); print1(denominator(s), ", "))};
%Y A383056 The unitary analog of A104529.
%Y A383056 Cf. A034444, A383055 (numerators).
%Y A383056 Similar sequences: A064608, A370898, A379514.
%K A383056 nonn,easy,frac
%O A383056 1,2
%A A383056 _Amiram Eldar_, Apr 15 2025