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 A095240 #15 Jul 08 2023 18:37:35
%S A095240 1,2,2,4,4,16,32,48,96,384,3072,9216,36864,46080,184320,483840,
%T A095240 3870720,7741440,82575360,743178240,23781703680,59454259200,
%U A095240 475634073600,2497078886400,39953262182400,22473709977600,85614133248000
%N A095240 Variant of A095236, where first two people choose payphones at the ends.
%C A095240 A non-monotonic sequence: a(25) > a(26).
%C A095240 a(n) > a(n+1) for n = 25, 33, 49, 57, 65, 81, 97, 98, 113, 129, 130, 131, 145, 161, 162, 177, 193, 194, 195, 197, ... - _Max Alekseyev_, Mar 14 2019
%H A095240 Max Alekseyev, <a href="/A095240/b095240.txt">Table of n, a(n) for n = 1..100</a>
%H A095240 Simon Wundling, <a href="https://arxiv.org/abs/2303.18175">About a combinatorial problem with n seats and n people</a>, arXiv:2303.18175 [math.CO], 2023. (German)
%F A095240 For n>1, a(n) = A095239(n-1)/(n-1) * 2. - _Max Alekseyev_, Mar 14 2019
%F A095240 For n>1, a(n) = 2 * Product_{j=1..n-1} 2^(d(n,j)) * (d(n,j))! * (b(n,j) - d(n,j))! (See A095236 for definition and calculation of b(n,j) and d(n,j)). - _Simon Wundling_, May 21 2023
%e A095240 For example, in a 6-pay-phone situation, person A must pick either pay-phone 1 or pay-phone 6.
%Y A095240 Cf. A095236, A095239.
%K A095240 nonn
%O A095240 1,2
%A A095240 _Matthew Vandermast_, Jul 03 2004
%E A095240 Edited by _Max Alekseyev_, Mar 14 2019