login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A189559 Least prime k such that x' = k has n solutions, where x' is the arithmetic derivative (A003415) of x. 3
2, 5, 31, 167, 151, 491, 983, 887, 311, 1151, 1559, 2111, 1031, 2711, 4391, 4271, 3671, 3191, 5351, 9551, 11471, 14759, 8951, 13751, 11831, 5591, 19991, 10391, 15791, 28031, 30071, 37511, 43151, 27191, 40031, 31391, 52631, 53231, 35591, 52391, 50951 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
COMMENTS
It is much easier finding composite numbers having many solutions. See A189558. For odd numbers, see A189560.
REFERENCES
See A003415.
LINKS
FORMULA
a(n) is the least prime k such that A099302(k) = n.
CROSSREFS
Sequence in context: A266478 A107389 A261750 * A077483 A119242 A068145
KEYWORD
nonn
AUTHOR
T. D. Noe, Apr 24 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 15 19:27 EDT 2024. Contains 374334 sequences. (Running on oeis4.)