A068954 Smallest prime factor of n^n-(n-1)^(n-1).

3, 23, 229, 19, 101, 776887, 3, 7, 29, 275311670611, 5, 28201, 3, 52489, 109, 808793517812627212561, 9680119, 5, 3, 1137694897331, 3697, 29, 6361, 10667, 3, 23, 17787551, 41393681953973, 7, 4211, 3, 461, 83, 19, 31, 983, 3, 5, 89, 2251, 250460976091, 109, 3, 29

Offset

2,1

Links

Chai Wah Wu, Table of n, a(n) for n = 2..107

Formula

a(n) = A020639(A007781(n)).

Example

A007781(14) = 10809131718965763 = 3 * 61^2 * 968299894201, therefore a(14) = 3.

Crossrefs

Cf. A020639, A007781, A068955, A068956.

Sequence in context: A206763 A306154 A201205 * A068955 A151393 A007781

Adjacent sequences: A068951 A068952 A068953 * A068955 A068956 A068957

Keyword

nonn

Author

Reinhard Zumkeller, Mar 11 2002

Extensions

a(20)-a(40) from Daniel Starodubtsev, Mar 10 2019

a(41)-a(45) from Chai Wah Wu, Jul 15 2019

Status

approved