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 A062819 #15 Feb 08 2025 04:51:41
%S A062819 6,34,502,8162,33550342,8589869586,137438691334,2305843008139960290,
%T A062819 2658455991569831744654692615953842678,
%U A062819 191561942608236107294793378084303638130997321581719586,13164036458569648337239753460458722910223472318386943117783728134
%N A062819 Inverse Moebius transform of perfect numbers, A000396.
%H A062819 Amiram Eldar, <a href="/A062819/b062819.txt">Table of n, a(n) for n = 1..15</a>
%H A062819 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>.
%F A062819 a(n) = Sum_{d|n} A000396(d). - _Amiram Eldar_, Feb 08 2025
%t A062819 a[n_] := DivisorSum[n, PerfectNumber[#] &]; Array[a, 11] (* _Amiram Eldar_, Feb 08 2025 *)
%Y A062819 Cf. A000396.
%K A062819 nonn
%O A062819 1,1
%A A062819 _Labos Elemer_, Jul 20 2001
%E A062819 Offset corrected and a(11) added by _Amiram Eldar_, Feb 08 2025