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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A075715 Numbers n such that 1+n+n^s is a prime, s=16. 2
1, 2, 21, 26, 47, 65, 99, 102, 206, 215, 216, 257, 294, 342, 437, 441, 537, 540, 702, 747, 837, 860, 909, 912, 921, 926, 942, 1020, 1071, 1101, 1112, 1125, 1181, 1254, 1266, 1322, 1344, 1364, 1370, 1406, 1422, 1665, 1814, 1821, 1829, 1905, 2024 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

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=16 and find several first n's making n_s a prime (or a probable prime).

EXAMPLE

2 is OK because at s=16, n=2, n_s=1+n+n^s=65539 is a prime.

PROG

(PARI) for(n=1, 3000, if(isprime(1+n+n^16), print1(n", ")))

CROSSREFS

Cf. A002384, A075714, A075716.

Sequence in context: A135053 A042565 A079907 * A071761 A101316 A006920

Adjacent sequences:  A075712 A075713 A075714 * A075716 A075717 A075718

KEYWORD

nonn

AUTHOR

Zak Seidov (zakseidov(AT)yahoo.com), Oct 03 2002

EXTENSIONS

More terms from Ralf Stephan (ralf(AT)ark.in-berlin.de), Mar 19 2003

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 12:25 EST 2012. Contains 205786 sequences.