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 A236554 #14 Feb 01 2014 09:01:56
%S A236554 8,64,288,1056,4128,16416,65568,262176
%N A236554 Number of involutions in the quaternion ring over Z/(2^n)Z with i^2=j^2=1.
%F A236554 a(n) = A236553(2^n).
%t A236554 invo11[n_] := Length@Reduce[a^2 - b^2 + c^2 + d^2 ==1 && 2 a b== 0 && 2 a c == 0 && 2 a d == 0, Modulus -> n];Table[invo11[2^n],{n,8}]
%Y A236554 Cf. A236553, A227867.
%K A236554 nonn,more,hard
%O A236554 1,1
%A A236554 _José María Grau Ribas_, Jan 28 2014