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.
%I A327158 #16 Jan 05 2025 19:51:41
%S A327158 1,6,60,90,87360
%N A327158 Unitary multiply-perfect numbers: n divides usigma(n), where usigma is the sum of unitary divisors of n (A034448).
%C A327158 10^13 < a(6) <= 146361946186458562560000. - _Giovanni Resta_, Aug 29 2019
%H A327158 Peter Hagis, Jr., <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/25-2/hagis.pdf">Lower bounds for unitary multiperfect numbers</a>, Fibonacci Quarterly, Vol. 22, No. 2 (1984), pp. 140-143.
%o A327158 (PARI)
%o A327158 A034448(n) = { my(f=factorint(n)); prod(k=1, #f~, 1+(f[k, 1]^f[k, 2])); }; \\ After code in A034448
%o A327158 isA327158(n) = (gcd(n,A034448(n))==n);
%Y A327158 Fixed points of A323166, positions of zeros in A327164.
%Y A327158 Cf. A002827 (a subsequence), A034448, A327163.
%Y A327158 Cf. also A007691.
%K A327158 nonn,more
%O A327158 1,2
%A A327158 _Antti Karttunen_, Aug 28 2019