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 A209248 #25 Feb 11 2020 09:57:42
%S A209248 2,128,2097152,2251799813685248,10384593717069655257060992658440192,
%T A209248 883423532389192164791648750371459257913741948437809479060803100646309888
%N A209248 a(n) = 2^(2^n - 2*n - 1).
%C A209248 a(n) = 2^A070313(n). Krotov on p. 2: "in general, two extended Hamming codes can intersect in 2^(2^m - 2m - 1) elements."
%H A209248 Denis Krotov, <a href="http://arxiv.org/abs/1210.0010">A partition of the hypercube into cosets of maximally nonparallel Hamming codes</a>, arXiv:1210.0010v1 [cs.IT], 2012-2016.
%H A209248 <a href="/index/Di#divseq">Index to divisibility sequences</a>
%e A209248 a(5) = 2^(2^5 - 2*5 - 1) = 2^21 = 2097152.
%t A209248 Table[2^(2^n - 2n - 1), {n, 3, 15}] (* _Alonso del Arte_, Jan 13 2013 *)
%o A209248 (PARI) 1<<(2^n-2*n-1) \\ _Charles R Greathouse IV_, Jan 24 2013
%o A209248 (Maxima) makelist(floor(2^(2^n-2*n-1)),n,3,8); /* _Martin Ettl_, Jan 25 2013 */
%Y A209248 Cf. A070313.
%K A209248 nonn,easy
%O A209248 3,1
%A A209248 _Jonathan Vos Post_, Jan 13 2013