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 A102360 #9 Feb 21 2020 09:29:37 %S A102360 1,15,80,961,2802,52800,142020,2347506,10512320,96837120,329849040, %T A102360 8619170560,16148168402,221483030400,1146781040640,14442767744328, %U A102360 38774519976900,813898294809600,1904350030969680,35410174950039552 %N A102360 a(n) = sigma((7^n - 1)/6), where sigma(n) is the sum of positive divisors of n. %H A102360 Amiram Eldar, <a href="/A102360/b102360.txt">Table of n, a(n) for n = 1..378</a> %F A102360 a(n) = A000203(A023000(n)). - _Amiram Eldar_, Feb 21 2020 %o A102360 (PARI) a(n) = sigma((7^n - 1)/6); \\ _Michel Marcus_, Feb 21 2020 %Y A102360 Cf. A000203, A023000. %K A102360 nonn %O A102360 1,2 %A A102360 Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Feb 22 2005