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Least number k such that prime(n) divides T(k), the central trinomial coefficient A002426(k), or 0 if there is no such k.
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%I #5 Mar 30 2012 17:22:41

%S 0,2,0,3,0,0,5,4,0,0,0,0,8,9,6,0,0,0,0,0,9,0,0,0,0,0,0,26,47,12,0,7,0,

%T 0,0,0,0,0,0,28,44,0,31,51,0,61,0,0,0,0,27,0,0,0,0,0,89,0,90,135,98,

%U 48,122,120,0,0,0,0,121,0,0,0,0,112,0,91,0,0,55,63,133,48,0,0,126,179,0,78

%N Least number k such that prime(n) divides T(k), the central trinomial coefficient A002426(k), or 0 if there is no such k.

%C When a(n)=0, prime(n) is in A113305. When a(n)>0, prime(n) is in A113304.

%H T. D. Noe, <a href="/A113303/b113303.txt">Table of n, a(n) for n=1..1000</a>

%t 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}]]; Table[p=Prime[i]; k=1; While[k<nn && Mod[t[[k]], p]>0, k++ ]; If[k==nn, 0, k], {i, PrimePi[nn]}]

%Y Cf. A113302 (number of k for which prime(n) divides T(k)).

%K nonn

%O 1,2

%A _T. D. Noe_, Oct 24 2005