login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A282631 The smallest square referenced in A237043 (Numbers n such that 2^n - 1 is not squarefree, but 2^d - 1 is squarefree for every proper divisor d of n.). 2
9, 25, 49, 121, 289, 961, 529, 1194649, 1849, 5329, 841, 16129, 7921, 2209 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

A273043(1)=6, 2^6-1=63, 63=3*3*7, 63 is not squarefree and the square is 3*3=9.

CROSSREFS

Cf. A237043, A282632.

Sequence in context: A110284 A109367 A110588 * A245694 A045972 A297596

Adjacent sequences:  A282628 A282629 A282630 * A282632 A282633 A282634

KEYWORD

nonn

AUTHOR

Robert Price, Feb 19 2017

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 September 21 19:59 EDT 2019. Contains 327282 sequences. (Running on oeis4.)