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 A136363 #14 Aug 05 2024 05:20:40
%S A136363 23,3150,321582,32241015,3224590836,322466618438,32246696794797,
%T A136363 3224670272194238,322467032612360629,32246703337400266401,
%U A136363 3224670334173560419030,322467033423857340138979,32246703342405509396897775,3224670334241078180927002518,322467033424112509326065894640
%N A136363 a(n) = Sum_{ composite k, 1 <= k <= 10^n} (Sum of divisors d of k with 1 < d < k).
%H A136363 Amiram Eldar, <a href="/A136363/b136363.txt">Table of n, a(n) for n = 1..36</a> (calculated using the b-file at A072692)
%F A136363 a(n) = A072692(n) - 10^n*(10^n+3)/2 + 1. - _Max Alekseyev_, May 10 2009
%F A136363 a(n) ~ (Pi^2/12 - 1/2) * 10^(2*n). - _Amiram Eldar_, Aug 05 2024
%e A136363 a(1) = 23 because the divisors through 10^1 are as follows: 4 (2); 6 (2,3); 8 (2,4); 9 (3); 10 (2,5). The sum is 2 + 2 + 3 + 2 + 4 + 3 + 2 + 5 = 23.
%Y A136363 Cf. A072692, A136364.
%K A136363 nonn
%O A136363 1,1
%A A136363 _Enoch Haga_, Dec 26 2007, Dec 29 2007
%E A136363 Edited by _N. J. A. Sloane_, Jan 12 2008
%E A136363 Extended by _Max Alekseyev_, May 10 2009
%E A136363 a(13)-a(15) from _Amiram Eldar_, Aug 05 2024