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 A375230 #7 Aug 06 2024 11:14:56
%S A375230 1,3,3,3,3,9,3,9,3,9,3,9,3,9,9,3,3,9,3,9,9,9,3,27,3,9,9,9,3,27,3,9,9,
%T A375230 9,9,9,3,9,9,27,3,27,3,9,9,9,3,9,3,9,9,9,3,27,9,27,9,9,3,27,3,9,9,9,9,
%U A375230 27,3,9,9,27,3,27,3,9,9,9,9,27,3,9,3,9,3,27
%N A375230 The total number of infinitary divisors of the infinitary divisors of n.
%H A375230 Amiram Eldar, <a href="/A375230/b375230.txt">Table of n, a(n) for n = 1..10000</a>
%F A375230 a(n) = Sum_{d infinitary divisor of n} A037445(d).
%F A375230 Multiplicative with a(p^e) = 3^A000120(e).
%F A375230 a(n) = 3^A064547(n).
%F A375230 a(n) = A007425(n) if and only if n is squarefree (A005117).
%F A375230 a(n) = A074816(n) if and only if n is in A138302.
%t A375230 f[p_, e_] := 3^DigitCount[e, 2, 1]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100]
%o A375230 (PARI) a(n) = vecprod(apply(x -> 3^hammingweight(x), factor(n)[,2]));
%Y A375230 Cf. A000120, A005117, A037445, A064547, A077609, A138302.
%Y A375230 Similar sequences: A007425 (analogous with all the divisors), A074816 (unitary analog).
%K A375230 nonn,easy,mult
%O A375230 1,2
%A A375230 _Amiram Eldar_, Aug 06 2024