|
| |
|
|
A130761
|
|
Primes prime(n) such that at least one of the two numbers (prime(n+2)^2-prime(n)^2)/2 - 1 and (prime(n+2)^2-prime(n)^2)/2 + 1 is prime.
|
|
7
| |
|
|
3, 5, 7, 11, 13, 19, 29, 31, 37, 41, 43, 53, 59, 61, 67, 71, 79, 83, 97, 107, 127, 139, 149, 157, 179, 181, 191, 197, 227, 229, 239, 251, 263, 283, 293, 307, 347, 349, 353, 373, 419, 439, 443, 463, 467, 479, 499, 523, 541, 569, 601, 607, 613, 617, 619
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| (7^2 - 3^2)/2 - 1 is 19. Therefore 3 is in the sequence. (19^2 - 13^2)/2 + 1 is 97. Hence 13 is in the sequence.
|
|
|
MATHEMATICA
| Prime[Select[Range[140], PrimeQ[(Prime[ #+2]^2-Prime[ # ]^2)/2+1] || PrimeQ[(Prime[ # +2]^2-Prime[ # ]^2)/2-1] &]]
|
|
|
CROSSREFS
| Sequence in context: A020575 A055072 A059334 * A154966 A072667 A092729
Adjacent sequences: A130758 A130759 A130760 * A130762 A130763 A130764
|
|
|
KEYWORD
| nonn,less
|
|
|
AUTHOR
| J. M. Bergot (thekingfishb(AT)yahoo.ca), Jul 13 2007
|
|
|
EXTENSIONS
| Edited and extended by Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Jul 23 2007
|
| |
|
|
