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 A174932 #12 Sep 08 2022 08:45:51 %S A174932 1,4,6,16,10,54,14,96,45,130,22,1860,26,238,270,1216,34,6048,38,8300, %T A174932 504,550,46,335688,175,754,864,22484,58,811050,62,35200,1188,1258, %U A174932 1330,10095048,74,1558,1638,2576920,82,3113586,86,86372,92070,2254,94,255478416 %N A174932 a(n) = Sum_{d|n} A007955(d) * A000027(n/d) = Sum_{d|n} A007955(d) * (n/d), where A007955(m) = product of divisors of m. %H A174932 Andrew Howroyd, <a href="/A174932/b174932.txt">Table of n, a(n) for n = 1..1000</a> %F A174932 a(n) = n*A322671(n). - _Andrew Howroyd_, Jan 05 2020 %e A174932 For n = 4, A007955(n) = b(n): a(4) = b(1)*(4/1) + b(2)*(4/2) + b(4)*(4/4) = 1*4 + 2*2 + 8*1 = 16. %o A174932 (PARI) a(n)={n*sumdiv(n, d, vecprod(divisors(d))/d)} \\ _Andrew Howroyd_, Jan 05 2020 %o A174932 (Magma) [&+[&*Divisors(d)*(n div d):d in Divisors(n)]:n in [1..50]]; // _Marius A. Burtea_, Jan 05 2020 %o A174932 (Python) %o A174932 from math import isqrt %o A174932 from sympy import divisor_count, divisors %o A174932 def A174932(n): return n*sum(isqrt(d)**(c-2) if (c:=divisor_count(d)) & 1 else d**(c//2-1) for d in divisors(n,generator=True)) # _Chai Wah Wu_, Jun 25 2022 %Y A174932 Cf. A007955 (product of divisors), A322671. %K A174932 nonn %O A174932 1,2 %A A174932 _Jaroslav Krizek_, Apr 02 2010