%I A113305
%S A113305 2,5,11,13,23,29,31,37,53,59,61,67,71,79,83,89,97,101,103,127,137,139,
%T A113305 149,151,157,163,167,181,197,211,223,227,229,239,241,251,257,263,271,
%U A113305 313,317,331,337,349,353,359,367,379,389,397,431,433,449,461,463,479
%N A113305 Primes that do not divide any central trinomial coefficient, A002426.
%C A113305 For primes less than 10^6, the density of these primes is near 0.6075.
%t A113305 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 A113305 Cf. A113302 (number of k for which prime(n) divides T(k)), A113303 (least 
               k such that prime(n) divides T(k)).
%Y A113305 Sequence in context: A105961 A045361 A086081 this_sequence A095078 A062572 
               A106283
%Y A113305 Adjacent sequences: A113302 A113303 A113304 this_sequence A113306 A113307 
               A113308
%K A113305 nonn
%O A113305 1,1
%A A113305 T. D. Noe (noe(AT)sspectra.com), Oct 24 2005