%I #15 Dec 13 2015 07:54:55
%S 11,17,23,29,43,47,53,59,67,71,73,83,89,101,103,107,109,113,127,131,
%T 137,149,151,163,167,173,179,191,193,197,223,227,233,239,241,251,257,
%U 263,269,277,281,283,293,311,317,347,349,353,359,373,383,389,397,401,409,419,431,433,443,449,457,461,463,467,479,487,491,503
%N Fixed points of A265388: numbers n for which gcd{k=1..n-1} binomial(2*n, 2*k) = n.
%H Antti Karttunen, <a href="/A265402/b265402.txt">Table of n, a(n) for n = 1..1024</a>
%t Select[Range@ 504, GCD @@ Array[Function[k, Binomial[2 #, 2 k]], {# - 1}] == # &] (* _Michael De Vlieger_, Dec 11 2015 *)
%o (PARI) isok(n) = (n>1) && gcd(vector(n-1, k, binomial(2*n, 2*k))) == n; \\ _Michel Marcus_, Dec 08 2015, edited by _Antti Karttunen_, Dec 11 2015 (see A265388 for why).
%Y Fixed points of A265388. Cf. also A265403.
%K nonn
%O 1,1
%A _Antti Karttunen_, Dec 08 2015