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 A088841 #14 Mar 22 2024 06:49:13
%S A088841 8,8,8,8,8,8,57,8,8,8,8,8,8,57,8,8,8,8,8,8,57,8,8,8,8,8,8,57,8,8,8,8,
%T A088841 8,8,57,8,8,8,8,8,8,57,8,8,8,8,8,8,400,8,8,8,8,8,8,57,8,8,8,8,8,8,57,
%U A088841 8,8,8,8,8,8,57,8,8,8,8,8,8,57,8,8,8,8,8,8,57,8,8,8,8,8,8,57,8,8,8,8,8,8
%N A088841 Numerator of the quotient sigma(7*n)/sigma(n).
%H A088841 Amiram Eldar, <a href="/A088841/b088841.txt">Table of n, a(n) for n = 1..10000</a>
%F A088841 From _Amiram Eldar_, Mar 22 2024: (Start)
%F A088841 a(n) = numerator(A283078(n)/A000203(n)).
%F A088841 a(n) = (7^(A214411(n)+2)-1)/6 = (49*A268354(n)-1)/6.
%F A088841 Sum_{k=1..n} a(k) ~ (7/log(7))*n*log(n) + (9/2 + 7*(gamma-1)/log(7))*n, where gamma is Euler's constant (A001620).
%F A088841 Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k)/A088842(k) = 1 + 36 * Sum_{k>=1} 1/(7^k-1) = 7.87276224676... . (End)
%t A088841 Table[Numerator[DivisorSigma[1, 7*n]/DivisorSigma[1, n]], {n, 1, 128}]
%o A088841 (PARI) a(n) = numerator(sigma(7*n)/sigma(n)); \\ _Amiram Eldar_, Mar 22 2024
%Y A088841 Cf. A088837, A088838, A088839, A088840, A088841, A088842 (denominators).
%Y A088841 Cf. A000203, A038712, A080278, A214411, A268354, A283078.
%K A088841 nonn,easy,frac
%O A088841 1,1
%A A088841 _Labos Elemer_, Nov 04 2003