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.

A185032 Initial term of first run of exactly n consecutive numbers with 3 distinct prime factors.

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%I A185032 #35 Jun 23 2025 14:32:42
%S A185032 30,230,644,1308,2664,6850,10280,39693,44360,48919,218972,534078,
%T A185032 2699915,526095,17233173,127890362,29138958036,146216247221,
%U A185032 23671413563491,36966736685739
%N A185032 Initial term of first run of exactly n consecutive numbers with 3 distinct prime factors.
%C A185032 The number of distinct prime factors is A001221.
%C A185032 If any following terms exist, they are greater than 10^13.
%C A185032 Eggleton and MacDougall show that there are no more than 59 terms in this sequence.
%C A185032 a(19) <= 7523987244435061. - _Donovan Johnson_, Jul 08 2013
%C A185032 a(21) > 2 * 10^15, if it exists. - _Toshitaka Suzuki_, Jun 23 2025
%H A185032 Roger B. Eggleton and James A. MacDougall, <a href="http://www.jstor.org/stable/27643119">Consecutive integers with equally many principal divisors</a>, Math. Mag. 81 (2008), 235-248.
%H A185032 Roger B. Eggleton, Jason S. Kimberley, and James A. MacDougall, <a href="http://hdl.handle.net/1959.13/35886">Principal divisor ranks of the first trillion positive integers</a>, NOVA: The University of Newcastle’s Digital Research Repository (2009).
%e A185032 a(14) < a(13) because the first run of 13 consecutive integers i with A001221(i)=3 is not a maximal run.
%Y A185032 Cf. A080569, A064709, and A185042.
%K A185032 nonn,fini,more
%O A185032 1,1
%A A185032 Roger B. Eggleton, _Jason Kimberley_, and James A. MacDougall, Apr 12 2011
%E A185032 a(19)-a(20) from _Toshitaka Suzuki_, Mar 24 2025