|
Search: id:A075722
|
|
|
| A075722 |
|
1+n+n^s is a prime, s=7. |
|
+0
2
|
|
| 1, 2, 15, 21, 29, 39, 42, 53, 57, 77, 81, 92, 117, 123, 131, 147, 149, 153, 167, 168, 200, 204, 207, 233, 249, 251, 252, 275, 278, 314, 317, 326, 357, 372, 378, 380, 410, 422, 434, 438, 440, 462, 467, 468, 498, 516, 546, 585, 587, 596, 608, 615, 621, 636
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
For s = 5,8,11,14,17,20,..., n_s=1+n+n^s is always composite for any n>1. Also at n=1, n_s=3 is a prime for any s. So it is interesting to consider only the cases of s =/= 5,8,11,14,17,20,... and n>1. Here i consider the case s=7 and find several first n's making n_s a prime (or a probable prime).
|
|
LINKS
|
T. D. Noe, Table of n, a(n) for n=1..1000
|
|
EXAMPLE
|
15 is OK because at s=7, n=15, n_s=1+n+n^s=170859391 is a prime.
|
|
CROSSREFS
|
Cf. A002384, A075720, A075723.
Sequence in context: A076617 A091791 A143660 this_sequence A153712 A153711 A116049
Adjacent sequences: A075719 A075720 A075721 this_sequence A075723 A075724 A075725
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Zak Seidov (zakseidov(AT)yahoo.com), Oct 03 2002
|
|
EXTENSIONS
|
More terms from R. Stephan (ralf(AT)ark.in-berlin.de), Apr 05 2003
|
|
|
Search completed in 0.002 seconds
|
