login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A178981 2^A003418(n); for n >= 1, the least number > 1 that can be expressed simultaneously as a k-th power of some integer for all 1 <= k <= n. 0
2, 2, 4, 64, 4096, 1152921504606846976, 1152921504606846976 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Equivalently, for n >= 1, the least number > 1 of objects that can be arranged as a k-cube (k-dimensional 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 19 21:47 EST 2020. Contains 331066 sequences. (Running on oeis4.)