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 A325026 #14 May 10 2024 04:08:03 %S A325026 120,523776,1476304896,31998395520,518666803200,30823866178560, %T A325026 740344994887680,796928461056000,212517062615531520, %U A325026 69357059049509038080,87934476737668055040,170206605192656148480,1161492388333469337600,1802582780370364661760,1940351499647188992000 %N A325026 Multi-perfect numbers from A007691 that are not harmonic (A001599). %C A325026 Multi-perfect numbers m such that m*tau(m)/sigma(m) is not an integer, where tau(k) is the number of the divisors of k (A000005) and sigma(k) is the sum of the divisors of k (A000203). %C A325026 Supersequence of A046987. %C A325026 Complement of A325025 with respect to A007691. %H A325026 Amiram Eldar, <a href="/A325026/b325026.txt">Table of n, a(n) for n = 1..202</a> %e A325026 120 is a term because 120*tau(120)/sigma(120) = 120*16/360 = 16/3. %o A325026 (Magma) [n: n in [1..1000000] | not IsIntegral((NumberOfDivisors(n)) * n / SumOfDivisors(n)) and IsIntegral(SumOfDivisors(n)/n)] %o A325026 (PARI) isok(n) = my(s=sigma(n)); !frac(s/n) && frac(n*numdiv(n)/s); \\ _Michel Marcus_, Mar 24 2019 %Y A325026 Cf. A000005, A000203, A001599, A007691, A325025. %Y A325026 Cf. A140798 (harmonic numbers that are not multi-perfect). %K A325026 nonn %O A325026 1,1 %A A325026 _Jaroslav Krizek_, Mar 24 2019