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!)
A158245 Primitive numbers in A158235. 2
11, 20, 39, 49, 133, 247, 543, 1218, 1651, 1729, 2289, 3097, 4171, 4503, 6231, 7303, 7540, 7563, 8773, 9139, 12439, 16627, 16761, 17157, 20280, 22021, 22393, 37051, 37209, 37387, 45201, 47257, 51961, 65379, 66211, 69601, 100191, 103861, 105339 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The primitive terms in A158235 are the ones for which the repdigit is squarefree. Hence n^2 = d*(b^k-1)/(b-1) with d squarefree and d<b<n.

LINKS

Table of n, a(n) for n=1..39.

EXAMPLE

105339^2 = 333 in base 60817.

CROSSREFS

Sequence in context: A153368 A068600 A158235 * A076851 A164576 A058497

Adjacent sequences:  A158242 A158243 A158244 * A158246 A158247 A158248

KEYWORD

nonn

AUTHOR

T. D. Noe, Mar 14 2009

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 21 16:47 EST 2020. Contains 331114 sequences. (Running on oeis4.)