

A178981


2^A003418(n); for n >= 1, the least number > 1 that can be expressed simultaneously as a kth power of some integer for all 1 <= k <= n.


0




OFFSET

0,1


COMMENTS

Equivalently, for n >= 1, the least number > 1 of objects that can be arranged as a kcube (kdimensional hypercube) for all 1 <= k <= n.
a(7) = 2^420 contains 127 decimal digits.


LINKS

Table of n, a(n) for n=0..6.
Index to divisibility sequences


EXAMPLE

a(6) = 2^A003418(6) = 2^60 = 1152921504606846976 [= (2^60)^1] = (2^30)^2 = 1073741824^2 = (2^20)^3 = 1048576^3 = (2^15)^4 = 32768^4 = (2^12)^5 = 4096^5 = (2^10)^6 = 1024^6, while no smaller integer > 1 can be expressed simultaneously as a square, cube, 4th, 5th, and 6th power of integers.


CROSSREFS

Cf. A003418.
Sequence in context: A075806 A295580 A177956 * A050923 A326960 A067700
Adjacent sequences: A178978 A178979 A178980 * A178982 A178983 A178984


KEYWORD

nonn,easy


AUTHOR

Rick L. Shepherd, Jan 02 2011


STATUS

approved



