login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Duplicate of A082180.
2

%I #31 Aug 12 2018 17:24:10

%S 4,9,25,49,121,125,169,289,343,361,418,529,841,961,1331,1369,1681,

%T 1849,2197,2209,2809,3481,3721,4489,4913,5041,5329,6241,6859,6889,

%U 7921,9409,10201,10609,11449,11881,12167,12769,16129,17161,18769,19321,22201,22801,24389,24649,26569,27173

%N Duplicate of A082180.

%p 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 (PARI) a(file,nmax)={my(n=0,p=1);

%o while(1,p++;if(((binomial(2*p,p)-2)%p)==0,

%o if(!isprime(p),n++;write(file,n," ",p);if(n==nmax,break)));

%o );}

%K dead

%O 1,1

%A _Stanislav Sykora_, Aug 16 2014