|
Search: id:A105888
|
|
|
| A105888 |
|
a(n) = the smallest prime that, when written in binary, ends with the substring of 2n-1 in binary. |
|
+0
1
|
| |
|
|
OFFSET
|
1,1
|
|
|
EXAMPLE
|
2*5-1 = 9 is 1001 in binary. Looking at the binary numbers that end with 1001: 1001 = 9 in decimal is composite; 10010 = 18 in decimal is composite. But 10011 = 19 in decimal is prime. So a(5) = 19.
|
|
MATHEMATICA
|
pr=-16; Select[Prime[Range[200]], MultiplicativeOrder[pr, # ] == #-1 &]
|
|
CROSSREFS
|
A164022
Sequence in context: A142712 A147095 A161626 this_sequence A123632 A039868 A015723
Adjacent sequences: A105885 A105886 A105887 this_sequence A105889 A105890 A105891
|
|
KEYWORD
|
base,more,nonn
|
|
AUTHOR
|
Leroy Quet (q1qq2qqq3qqqq(AT)yahoo.com), Aug 08 2009
|
|
|
Search completed in 0.002 seconds
|
