A100757 Smallest prime factor of the concatenation of terms of the n-th row of the Stirling's number of the second kind.

11, 131, 3, 7, 101, 9066319, 3, 3, 89, 3, 1721, 13, 8761, 1213, 7, 3, 1056688498936034269, 37, 29, 3, 3, 11, 3, 19457, 7, 19, 11, 307, 3, 521, 7, 11887, 3, 3, 7, 3, 13, 11, 103, 43, 22927346902711843, 3, 17, 13, 31, 3, 3, 7, 3, 133811, 37, 11, 13

Offset

2,1

Comments

Sequences from other important triangles with unity as the first and the last term can be contributed.

A061113(8) is the first member of A061113 that is not squarefree; it is divisible by 3^3. - David Wasserman, Mar 06 2008

Links

Table of n, a(n) for n=2..54.

Formula

a(n) = A020639[A061113(n)]. - R. J. Mathar, Aug 07 2007

Example

a(4) = 3 is the least prime factor of 1761.

Crossrefs

Cf. A100755, A100756, A100758, A008277.

Sequence in context: A157718 A256957 A046210 * A099677 A142187 A201484

Adjacent sequences: A100754 A100755 A100756 * A100758 A100759 A100760

Keyword

base,easy,nonn

Author

Amarnath Murthy, Nov 23 2004

Extensions

More terms from R. J. Mathar, Aug 07 2007

More terms from David Wasserman, Mar 06 2008

Status

approved