|
Search: id:A139463
|
|
|
| A139463 |
|
Numbers n such that (product of the first n odd primes) - 2*prime(n+2) is a prime. |
|
+0
4
|
|
| 3, 4, 6, 10, 15, 42, 49, 56, 63, 106, 170, 182, 246, 255
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
EXAMPLE
|
3 is in the sequence because 3*5*7 - 2*11 = 83 is a prime.
|
|
MATHEMATICA
|
k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k - 2*Prime[n + 1]], AppendTo[a, n - 1]], {n, 2, 2000}]; a (*Artur Jasinski*)
|
|
CROSSREFS
|
Cf. A067026, A067027, A139439, A139440, A139441, A139442, A139443, A139444, A139445, A139446, A139447, A139448, A139449, A139450, A139451, A139452, A139453, A139454, A139455, A139456, A139457, A103514, A139460, A139461, A139462, A139463.
Sequence in context: A059618 A114736 A099417 this_sequence A068922 A032408 A018908
Adjacent sequences: A139460 A139461 A139462 this_sequence A139464 A139465 A139466
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Artur Jasinski (grafix(AT)csl.pl), Apr 22 2008
|
|
EXTENSIONS
|
Edited by Jens Kruse Andersen (jens.k.a(AT)get2net.dk), May 03 2008
|
|
|
Search completed in 0.002 seconds
|
