A100755 Smallest prime factor of the concatenation of terms in the n-th row of Pascal's Triangle.

11, 11, 11, 11, 7, 43, 29, 18285670562881, 5647, 13, 11, 523, 180642383, 41, 17, 7, 71, 31, 4506133, 13, 170777, 29, 1921778735419, 11, 31, 197, 13, 524243, 1294063654237511187554750201560780429214510015005200300103459729051895935678639157755876077558760678639155189593534597290200300101001500542921451560780475020118755237513654406291

Offset: 1

Author

Amarnath Murthy, Nov 23 2004

Keywords

• base
• nonn

Examples

			a(4) = 11 is the least prime factor of 14641 = 11^4.
a(5) = 7 as 15101051 = 7* 2157293.
		

Crossrefs

Cf. A100756.

Programs

Mathematica

f[n_] := (Table[ #[[1]], {1}] & /@ FactorInteger[ FromDigits[ Flatten[ Table[ IntegerDigits[ Binomial[n, k]], {k, 0, n}]]], FactorComplete -> False])[[1, 1]]; Table[ f[n], {n, 29}] (* Robert G. Wilson v, Dec 02 2004 *)

Extensions

More terms from Robert G. Wilson v, Dec 02 2004