A113303 Least number k such that prime(n) divides T(k), the central trinomial coefficient A002426(k), or 0 if there is no such k.

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, 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, 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

Offset

1,2

Comments

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

Links

T. D. Noe, Table of n, a(n) for n=1..1000

Mathematica

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]}]

Crossrefs

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

Sequence in context: A071391 A102390 A127640 * A080089 A322841 A291044

Adjacent sequences: A113300 A113301 A113302 * A113304 A113305 A113306

Keyword

nonn

Author

T. D. Noe, Oct 24 2005

Status

approved