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 A367553 #14 Nov 22 2023 10:48:22
%S A367553 2,18,128,1506,15552,266548,4194304,89452674,2010077696,52439799700,
%T A367553 1486016741376,46761291772836,1587429546508288,58431605635691172,
%U A367553 2305913377957871616,97342665226310447618,4371823119477393063936,208266120619720061526886
%N A367553 a(n) = Sum_{d|n} (d+n/d)^n.
%C A367553 a(n) is even.
%F A367553 a(n) = Sum_{k=0..n} n^(n-k) * binomial(n,k) * (Sum_{d|n} d^(2*k-n)) = Sum_{k=0..n} binomial(n,k) * (Sum_{d|n} d^k * (n/d)^(n-k)).
%o A367553 (PARI) a(n) = sumdiv(n, d, (d+n/d)^n);
%Y A367553 Cf. A074400.
%K A367553 nonn
%O A367553 1,1
%A A367553 _Seiichi Manyama_, Nov 22 2023