|
Search: id:A127260
|
|
|
| A127260 |
|
Indices n of odd numbers of the form 8*n+1 that are not primes. |
|
+0
2
|
|
| 0, 1, 3, 4, 6, 7, 8, 10, 13, 15, 16, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 31, 33, 34, 36, 37, 38, 40, 41, 43, 45, 46, 47, 48, 49, 52, 53, 55, 58, 59, 60, 61, 62, 63, 64, 66, 67, 68, 69, 70, 73, 76, 78, 79, 81, 82, 83, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 97, 98, 99, 100, 102
(list; graph; listen)
|
|
|
OFFSET
|
1,3
|
|
|
COMMENT
|
Could be generated from A045751 by removing all odd terms there, then halving each remaining term. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 08 2007
|
|
FORMULA
|
Let p=prime number, n=(p^2-1)/8 mod (p) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Jan 03 2009]
|
|
MAPLE
|
isA127260 := proc(n) not isprime(8*n+1) ; end: for n from 0 to 200 do if isA127260(n) then printf("%d, ", n) ; fi ; od ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 08 2007
|
|
MATHEMATICA
|
a = Flatten[Table[If[PrimeQ[8*n + 1] == False, n, {}], {n, 0, 50}]]
|
|
CROSSREFS
|
Cf. A045751.
Sequence in context: A007378 A087758 A105454 this_sequence A089530 A133512 A047515
Adjacent sequences: A127257 A127258 A127259 this_sequence A127261 A127262 A127263
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Roger L. Bagula (rlbagulatfttn(AT)yahoo.com), May 17 2007
|
|
EXTENSIONS
|
More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 08 2007
|
|
|
Search completed in 0.002 seconds
|
