|
Search: id:A138923
|
|
|
| A138923 |
|
Indices k such that A020506(k)=Phi[k](-7) is prime, where Phi is a cyclotomic polynomial. |
|
+0
1
|
|
| 3, 9, 10, 15, 17, 23, 25, 26, 27, 28, 29, 36, 42, 47, 48, 61, 76, 84, 110, 126, 148, 210, 224, 262, 280, 288, 296, 298, 325, 327, 332, 352, 365, 456, 513, 528, 740
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
There are only 6 terms between 365 and 1445 (exclusive).
|
|
LINKS
|
Yves Gallot, Cyclotomic polynomials and prime numbers
|
|
PROGRAM
|
(PARI) for( i=1, 999, ispseudoprime( polcyclo(i, -7)) & print1( i", ")) /* use ...subst(polcyclo(i), x, -7)... in PARI < 2.4.2 */
|
|
CROSSREFS
|
Cf. A020506, A138920-A138940.
Sequence in context: A066887 A030608 A118515 this_sequence A049096 A030794 A134073
Adjacent sequences: A138920 A138921 A138922 this_sequence A138924 A138925 A138926
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
M. F. Hasler (www.univ-ag.fr/~mhasler), Apr 03 2008
|
|
|
Search completed in 0.002 seconds
|
