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 A374915 #16 Jul 23 2024 10:48:55 %S A374915 0,0,8,42,72,240,240,630,728,1296,1080,3080,1848,3744,4368,6510,4320, %T A374915 10608,6120,14364,12160,15120,11088,30360,17112,25200,26000,39312, %U A374915 22680,58464,27840,58590,47616,57024,53856,108290,47880,79920,78736,133380,65520,157440 %N A374915 a(n) = (n - 1) * (n - 2) * sigma(n). %H A374915 William Craig, Jan-Willem van Ittersum, and Ken Ono, <a href="https://arxiv.org/abs/2405.06451">Integer partitions detect the primes</a>, arXiv:2405.06451v2 [math.CO], Jul 10 2024. %F A374915 a(n) = A002378(n-2) * A000203(n). %F A374915 a(n) >= 8 * A002127(n) and the equal sign only holds if n is 1 or prime. %t A374915 a[n_]:= (n - 1) * (n - 2) * DivisorSigma[1,n]; Array[a,42] (* _Stefano Spezia_, Jul 23 2024 *) %o A374915 (PARI) a(n) = (n-1)*(n-2)*sigma(n); %Y A374915 Cf. A000203, A002127, A002378, A060043, A078837. %K A374915 nonn %O A374915 1,3 %A A374915 _Seiichi Manyama_, Jul 23 2024