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 A118988 #21 Sep 21 2024 14:27:13 %S A118988 1,2,2,4,7,15,20,62,190,771,2073 %N A118988 Number of different values taken by the permanent of a symmetric real (+1,-1)-matrix of order n. %H A118988 Minfeng Wang, <a href="/A118988/a118988_1.cpp.txt">C++ program</a>. %Y A118988 Cf. A087983, A118987, A118986. %Y A118988 Cf. A006125 (number of symmetric real (+1,-1)-matrices of order (n-1)). %K A118988 nonn,more %O A118988 0,2 %A A118988 _Giovanni Resta_, May 08 2006 %E A118988 a(8)-a(9) from _Minfeng Wang_, Jun 20 2024 %E A118988 a(0)=1 prepended by _Alois P. Heinz_, Jun 21 2024 %E A118988 a(10) from _Minfeng Wang_, Sep 21 2024