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

1,1

Links

Table of n, a(n) for n=1..29.

Example

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

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 *)

Crossrefs

Cf. A100756.

Sequence in context: A366717 A212541 A087994 * A171902 A337241 A045538

Adjacent sequences: A100752 A100753 A100754 * A100756 A100757 A100758

Keyword

base,nonn

Author

Amarnath Murthy, Nov 23 2004

Extensions

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

Status

approved