|
|
A171140
|
|
Numbers k such that 6*k + 7 = p^2 (p=prime).
|
|
1
|
|
|
3, 7, 19, 27, 47, 59, 87, 139, 159, 227, 279, 307, 367, 467, 579, 619, 747, 839, 887, 1039, 1147, 1319, 1567, 1699, 1767, 1907, 1979, 2127, 2687, 2859, 3127, 3219, 3699, 3799, 4107, 4427, 4647, 4987, 5339, 5459, 6079, 6207, 6467, 6599, 7419, 8287, 8587
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
6*3 + 7 = 5^2, so 3 is a term;
6*7 + 7 = 7^2, so 7 is a term;
6*19 + 7 = 11^2, so 19 is a term;
6*27 + 7 = 13^2, so 27 is a term.
|
|
MATHEMATICA
|
|
|
PROG
|
(Magma) [(p^2-7)/6: p in PrimesInInterval(4, 250)]; // Vincenzo Librandi, Apr 06 2013
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|