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 A246131 #31 Aug 12 2018 17:24:10
%S A246131 4,9,25,49,121,125,169,289,343,361,418,529,841,961,1331,1369,1681,
%T A246131 1849,2197,2209,2809,3481,3721,4489,4913,5041,5329,6241,6859,6889,
%U A246131 7921,9409,10201,10609,11449,11881,12167,12769,16129,17161,18769,19321,22201,22801,24389,24649,26569,27173
%N A246131 Duplicate of A082180.
%p A246131 select(n -> not isprime(n) and coeff(Power(1+x,2*n) mod n, x, n) = 2, [$4 .. 10000]); # _Robert Israel_, Sep 22 2014
%o A246131 (PARI) a(file,nmax)={my(n=0,p=1);
%o A246131 while(1,p++;if(((binomial(2*p,p)-2)%p)==0,
%o A246131 if(!isprime(p),n++;write(file,n," ",p);if(n==nmax,break)));
%o A246131 );}
%K A246131 dead
%O A246131 1,1
%A A246131 _Stanislav Sykora_, Aug 16 2014