|
Search: id:A120946
|
|
|
| A120946 |
|
Least positive k such that Z(n) + k is prime, where Z(n) = 1357986420*(10^(10*n)-1)/(10^10-1). |
|
+0
1
|
|
| 11, 29, 67, 179, 113, 53, 193, 143, 103, 173, 793, 181, 43, 263, 601, 839, 13, 331, 179, 167, 841, 59, 557, 359, 2437, 139, 113, 317, 109, 389, 551, 3517, 757, 187, 1327, 829, 401, 523, 811, 487, 563, 1909, 473, 703, 583, 2131, 1751
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
The majority of the decimal expansions of these (probable) primes have the pattern 13579864201357986420..., e.g. a(3)=67 and Z(3) + 67 = 135798642013579864201357986487. a(1001)=4637. Proof: PFGW Version 1.2.0 for Windows [FFT v23.8] Primality testing 1357986420*(10^(10*1001)-1)/(10^10-1)+4637 [N-1/N+1, Brillhart-Lehmer-Selfridge] Running N-1 test using base 3 Running N+1 test using discriminant 7, base 1+sqrt(7) Running N+1 test using discriminant 7, base 2+sqrt(7) 1357986420*(10^(10*1001)-1)/(10^10-1)+4637 is Fermat and Lucas PRP!
|
|
CROSSREFS
|
Sequence in context: A056256 A043139 A043919 this_sequence A099909 A106881 A106880
Adjacent sequences: A120943 A120944 A120945 this_sequence A120947 A120948 A120949
|
|
KEYWORD
|
nonn,less
|
|
AUTHOR
|
Jason Earls (zevi_35711(AT)yahoo.com), Aug 19 2006
|
|
|
Search completed in 0.002 seconds
|
