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.

A132587 Let b(k) be the k-th term of the flattened irregular array where the m-th row contains the positive divisors of m. (b(k) = A027750(k).) Let c(k) be the k-th term of the flattened irregular array where the m-th row contains the positive integers that are <= m and are coprime to m. (c(k) = A038566(k).) Then a(n) = gcd(b(n),c(n)).

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%I A132587 #9 Feb 07 2019 15:13:08
%S A132587 1,1,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,2,1,1,1,1,1,1,2,5,1,1,1,1,1,3,1,2,
%T A132587 3,1,1,1,1,1,1,1,1,5,1,1,1,2,1,4,1,1,1,2,3,2,1,6,1,1,1,1,1,1,1,2,1,1,
%U A132587 1,1,1,2,1,1,1,1,1,1,1,1,1,2,3,4,1,1,1
%N A132587 Let b(k) be the k-th term of the flattened irregular array where the m-th row contains the positive divisors of m. (b(k) = A027750(k).) Let c(k) be the k-th term of the flattened irregular array where the m-th row contains the positive integers that are <= m and are coprime to m. (c(k) = A038566(k).) Then a(n) = gcd(b(n),c(n)).
%H A132587 Rémy Sigrist, <a href="/A132587/b132587.txt">Table of n, a(n) for n = 1..10000</a>
%H A132587 Rémy Sigrist, <a href="/A132587/a132587.gp.txt">PARI program for A132587</a>
%e A132587 A027750: 1, 1, 2, 1, 3, 1, 2, 4, 1, 5, 1, 2, 3, 6, ...
%e A132587 A038566: 1, 1, 1, 2, 1, 3, 1, 2, 3, 4, 1, 5, 1, 2, ...
%e A132587 The 14th terms of each list are 6 and 2.
%e A132587 So a(14) = gcd(6,2) = 2.
%o A132587 (PARI) See Links section.
%Y A132587 Cf. A132588, A132589, A027750, A038566.
%K A132587 nonn
%O A132587 1,8
%A A132587 _Leroy Quet_, Aug 23 2007
%E A132587 More terms from _Rémy Sigrist_, Feb 07 2019