A069022 Start of the first occurrence of two consecutive numbers divisible by an n-th power.

1, 8, 80, 80, 1215, 16767, 76544, 636416, 3995648, 24151040, 36315135, 689278976, 1487503359, 1487503359, 155240824832, 785129144319, 4857090670592, 45922887663615, 157197025673216, 1375916505694208, 2280241934368767

Offset

1,2

Comments

Essentially the same as A063528. [R. J. Mathar, Sep 29 2008]

Links

Table of n, a(n) for n=1..21.

Example

(8, 9) is the first occurrence of two consecutive numbers divisible by a square, so a(2) = 8.

Mathematica

a = {1, 1}; k = 4; Do[ While[Min[a] < n, k++; a = Drop[a, 1]; a = Append[ a, Max[ Transpose[ FactorInteger[k]] [[2]] ]]]; Print[k - 1], {n, 2, 9}] (* Robert G. Wilson v *)

Crossrefs

Cf. A069021.

Sequence in context: A289213 A201513 A344660 * A217401 A077333 A216997

Adjacent sequences: A069019 A069020 A069021 * A069023 A069024 A069025

Keyword

nonn

Author

Amarnath Murthy, Apr 02 2002

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Oct 12 2003

Status

approved