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.

A239630 Factored over the Gaussian integers, the least number having n prime factors, excluding units 1, -1, i, and -i.

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%I A239630 #9 Jun 27 2020 04:32:06
%S A239630 2,5,10,30,130,390,2210,6630,46410,192270,1345890,7113990,49797930,
%T A239630 291673590,2041715130
%N A239630 Factored over the Gaussian integers, the least number having n prime factors, excluding units 1, -1, i, and -i.
%C A239630 From _Amiram Eldar_, Jun 27 2020: (Start)
%C A239630 Indices of records of A086275.
%C A239630 Also, numbers with a record number of unitary divisors in Gaussian integers (A332476). (End)
%t A239630 nn = 12; t = Table[0, {nn}]; n = 0; found = 0; While[found < nn, n++; f = FactorInteger[n, GaussianIntegers -> True]; cnt = Length[f]; If[MemberQ[{-1, I, -I}, f[[1, 1]]], cnt--]; If[cnt <= nn && t[[cnt]] == 0, t[[cnt]] = n; found++]]; t
%Y A239630 Cf. A001221, A001222 (integer factorizations).
%Y A239630 Cf. A078458, A086275 (Gaussian factorizations).
%Y A239630 Cf. A239627 (number of Gaussian factors of n, including units).
%Y A239630 Cf. A239628 (similar to this sequence, but count all prime factors).
%Y A239630 Cf. A239629 (number of distinct factors, including units).
%Y A239630 Cf. A332476.
%K A239630 nonn,more
%O A239630 1,1
%A A239630 _T. D. Noe_, Mar 31 2014
%E A239630 a(13)-a(15) from _Amiram Eldar_, Jun 27 2020