cp's OEIS Frontend

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.

A323172 Denominator of the average of distinct prime factors of n (A008472(n)/A001221(n)).

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%I A323172 #12 Sep 17 2024 04:03:36
%S A323172 1,1,1,1,2,1,1,1,2,1,2,1,2,1,1,1,2,1,2,1,2,1,2,1,2,1,2,1,3,1,1,1,2,1,
%T A323172 2,1,2,1,2,1,1,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,3,1,2,1,1,1,3,1,2,1,
%U A323172 3,1,2,1,2,1,2,1,1,1,2,1,2,1,1,1,2,1,2,1,3,1,2,1,2,1,2,1,2,1,2,1,3,1,2,1,2
%N A323172 Denominator of the average of distinct prime factors of n (A008472(n)/A001221(n)).
%H A323172 Antti Karttunen, <a href="/A323172/b323172.txt">Table of n, a(n) for n = 2..65539</a>
%t A323172 a[n_] := Denominator[Mean[FactorInteger[n][[;; , 1]]]]; Array[a, 100, 2] (* _Amiram Eldar_, Sep 17 2024 *)
%o A323172 (PARI)
%o A323172 A008472(n) = vecsum(factor(n)[, 1]); \\ From A008472
%o A323172 A323172(n) = (denominator(A008472(n)/omega(n)));
%Y A323172 Cf. A323171 (numerators).
%Y A323172 Cf. A001221, A008472, A123529, A322591.
%K A323172 nonn,easy,frac
%O A323172 2,5
%A A323172 _Antti Karttunen_, Jan 05 2019