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.

A323056 Numbers with exactly five distinct exponents in their prime factorization, or five distinct parts in their prime signature.

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%I A323056 #18 Feb 17 2019 20:40:29
%S A323056 174636000,206388000,244490400,261954000,269892000,274428000,
%T A323056 288943200,291060000,301644000,309582000,343980000,349272000,
%U A323056 365148000,366735600,377848800,383292000,404838000,411642000,412776000,422301600,433414800,449820000,452466000,457380000
%N A323056 Numbers with exactly five distinct exponents in their prime factorization, or five distinct parts in their prime signature.
%C A323056 The first term is A006939(5) = 174636000.
%C A323056 Positions of 5's in A071625.
%C A323056 Numbers k such that A001221(A181819(k)) = 5.
%H A323056 David A. Corneth, <a href="/A323056/b323056.txt">Table of n, a(n) for n = 1..10000</a>
%e A323056 174636000 = 2^5 * 3^4 * 5^3 * 7^2 * 11^1 has five distinct exponents so belongs to the sequence.
%t A323056 Select[Range[300000000],Length[Union[Last/@FactorInteger[#]]]==5&]
%o A323056 (PARI) is(n) = #Set(factor(n)[, 2]) == 5 \\ _David A. Corneth_, Jan 12 2019
%Y A323056 One distinct exponent: A062770 or A072774.
%Y A323056 Two distinct exponents: A323055.
%Y A323056 Three distinct exponents: A323024.
%Y A323056 Four distinct exponents: A323025.
%Y A323056 Five distinct exponents: A323056.
%Y A323056 Cf. A001221, A001222, A006939, A051270, A059404, A071625, A118914, A181819, A182855, A323014, A323022, A323024.
%K A323056 nonn
%O A323056 1,1
%A A323056 _Gus Wiseman_, Jan 03 2019
%E A323056 a(13)-a(24) from _Daniel Suteu_, Jan 12 2019