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 A225371 #55 Jan 28 2021 20:58:09
%S A225371 1,2,10,260,31096,13711952,28275659056,224402782202048,
%T A225371 7293836994286696576,952002419516769475035392,
%U A225371 497678654312172407869125822976,1044660329769242614113093804053562368,8745525723307044762290950664928498588583936
%N A225371 a(n) = number of squares in M(n,2), the ring of n X n matrices over GF(2).
%C A225371 a(0)-a(4) computed by _W. Edwin Clark_, May 07 2013.
%C A225371 A226321 is a similar sequence which counts the real {0,1} matrices which are the square of a {0,1} matrix. - _Giovanni Resta_, Jun 03 2013
%H A225371 Victor S. Miller, <a href="/A225371/b225371.txt">Table of n, a(n) for n = 0..30</a>
%H A225371 Victor S. Miller, <a href="http://arxiv.org/abs/1606.09299">Counting Matrices that are Squares</a>, arXiv:1606.09299 [math.GR], 2016.
%H A225371 Giovanni Resta, <a href="/A225371/a225371.c.txt">C program for a(k), with k <= 6.</a>
%H A225371 <a href="/index/Mat#binmat">Index entries for matrices, binary, which are squares</a>
%o A225371 (PARI) a(n)=#vecsort(lift(vector(2^n^2,k,matrix(n,n,i,j,bittest(k,(i-1)*n+j-1))^2*Mod(1,2))),,8) \\ _Charles R Greathouse IV_, May 07 2013
%o A225371 (PARI) ZM(k)=matrix(n,n,i,j,bittest(k,(i-1)*n+j-1))*Mod(1,2)
%o A225371 MZ(M)=my(n=matsize(M)[1]);sum(i=1,n,sum(j=1,n,M[i,j]<<((i-1)*n+j-1)))
%o A225371 a(n)=#vecsort(vector(2^n^2,i,MZ(lift(ZM(i,n)^2))),,8) \\ _Charles R Greathouse IV_, May 07 2013
%Y A225371 Cf. A226321, A121231, A266462, A274313.
%K A225371 nonn,hard
%O A225371 0,2
%A A225371 _N. J. A. Sloane_, May 07 2013
%E A225371 a(5)-a(6) from _Giovanni Resta_, May 08 2013
%E A225371 a(7)-a(30) from _Victor S. Miller_, May 24 2013