%I A113304
%S A113304 3,7,17,19,41,43,47,73,107,109,113,131,173,179,191,193,199,233,269,277,
%T A113304 281,283,293,307,311,347,373,383,401,409,419,421,439,443,457,467,503,
%U A113304 509,521,547,563,569,593,613,617,631,653,673,691,701,709,719,739,743
%N A113304 Primes that divide some central trinomial coefficient, A002426.
%C A113304 For primes less than 10^6, the density of these primes is near 0.3925.
%t A113304 nn=1000; a=b=1; t=Join[{1}, Table[c=((2n-1)b+3(n-1)a)/n; a=b; b=c; c, 
               {n, 2, nn}]]; pLst={}; Do[p=Prime[n]; k=1; While[k<p && Mod[t[[k]], 
               p]>0, k++ ]; If[k<p, AppendTo[pLst, p]], {n, PrimePi[nn]}]; pLst
%Y A113304 Cf. A113302 (number of k for which prime(n) divides T(k)), A113303 (least 
               k such that prime(n) divides T(k)).
%Y A113304 Sequence in context: A140863 A076194 A064699 this_sequence A093651 A018411 
               A083989
%Y A113304 Adjacent sequences: A113301 A113302 A113303 this_sequence A113305 A113306 
               A113307
%K A113304 nonn
%O A113304 1,1
%A A113304 T. D. Noe (noe(AT)sspectra.com), Oct 24 2005