|
| |
|
|
A078777
|
|
a(n) = the least positive integer k such that binomial(2k,k) + k + n is prime, if such k exists; = 0, otherwise.
|
|
0
| |
|
|
0, 1, 2, 1, 2, 3, 6, 1, 2, 1, 2, 5, 120, 1, 2, 1, 6, 3, 58, 1, 2, 7, 2, 3, 12, 1, 4, 1, 2, 3, 12, 9, 2, 1, 2, 3, 6, 1, 2, 1, 6, 19, 16, 1, 2, 13, 6, 3, 12, 1, 2, 7, 2, 5, 16, 1, 4, 1, 2, 3, 6, 15, 2, 1, 2, 3, 6, 1, 14, 1, 2, 7, 16, 3, 2, 1, 4, 3, 6, 1
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
COMMENTS
| The value a(1) = 0 is conjectural. There is no k < 8.5 x 10^3 such that binomial[2k,k]+k+1 is prime.
|
|
|
EXAMPLE
| k=2 is the least positive integer such that binomial(2k,k) + k + 3 is prime. Hence a(2) = 3.
|
|
|
CROSSREFS
| Sequence in context: A204994 A132405 A057192 * A135938 A079210 A070861
Adjacent sequences: A078774 A078775 A078776 * A078778 A078779 A078780
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Jan 09 2003
|
| |
|
|
