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 A081867 #13 Jan 08 2025 02:47:49
%S A081867 1,177148,48828126,1977326744,31381236757,285311670612,1792160394038,
%T A081867 8649804864648,34271896307634,116490258898220,350279478046112,
%U A081867 952809757913928,2384185839843751,5559091947792280,12200509765705830,25408476896404832,50542391825574576,96549159399201744
%N A081867 a(n) = sigma_11(2n-1).
%F A081867 Sum_{k=1..n} a(k) ~ c * n^12, where c = 691 * Pi^12 / 3742200 = 170.666988... . - _Amiram Eldar_, Jan 07 2025
%t A081867 Table[DivisorSigma[11,2n-1],{n,20}] (* _Harvey P. Dale_, Jun 26 2012 *)
%o A081867 (PARI) a(n) = sigma(2*n-1, 11); \\ _Amiram Eldar_, Jan 08 2025
%Y A081867 Cf. A013959.
%K A081867 nonn
%O A081867 1,2
%A A081867 _Benoit Cloitre_, Apr 12 2003