|
| |
|
|
A106041
|
|
Numbers n such that n*prime(n)-1 is a perfect square.
|
|
0
| | |
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Next term, if it exists, is >400000. - 397706 from Emeric Deutsch (deutsch(AT)duke.poly.edu), May 31 2005
a(11) > pi(4*10^12). [From Donovan Johnson (donovan.johnson(AT)yahoo.com), Oct 22 2010]
|
|
|
EXAMPLE
| 1*2-1=1^2
10*29-1=17^2
50*229-1=107^2
4946*47981-1=15405^2
|
|
|
CROSSREFS
| Sequence in context: A124872 A072296 A143558 * A143855 A124162 A077044
Adjacent sequences: A106038 A106039 A106040 * A106042 A106043 A106044
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Zak Seidov (zakseidov(AT)yahoo.com), May 06 2005
|
|
|
EXTENSIONS
| 397706 from Emeric Deutsch (deutsch(AT)duke.poly.edu), May 31 2005
4 more terms from Ryan Propper (rpropper(AT)stanford.edu), Oct 16 2005
a(10) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Oct 22 2010
|
| |
|
|
