A061113 -id:A061113 - cp's OEIS frontend

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

Amarnath Murthy, Nov 23 2004

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

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

Cf. A100755, A100756, A100758, A008277.

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

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

More terms from David Wasserman, Mar 06 2008

A100758 Greatest prime factor of the concatenation of terms of the n-th row of the triangle formed by the Stirling number of the second kind.

Original entry on oeis.org

11, 131, 587, 1646443, 6827, 18011869, 9120065483, 363724245921599, 975761724248252813688864599, 17542508725666616033, 111131968773953028264114836512440131291369683

Offset: 2

Amarnath Murthy, Nov 23 2004

Are these concatenations squarefree?

			a(4) = 587 is the greatest prime factor of 1761 =3*587.

Cf. A100755, A100756, A100757, A008277.

a(n) = A006530[A061113(n)]. - R. J. Mathar, Aug 07 2007

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

cp's OEIS Frontend

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

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