|
| |
|
|
A109615
|
|
Primes of the form floor((Pi/2)^n).
|
|
1
| | |
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| The given terms of the sequence correspond to n=2, 3, 7, 8, 16, 18, 20 respectively. There are no other terms for n=21..100000. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 27 2007
|
|
|
LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 1..14
|
|
|
EXAMPLE
| A014214(20) = floor((Pi/2)^20) = floor(8363.6825...) = 8363 and 8363 = A000040(1047), therefore 8363 is a term.
|
|
|
MAPLE
| a:=proc(n) if isprime(floor(((1/2)*Pi)^n))=true then floor(((1/2)*Pi)^n) else end if end proc: seq(a(n), n=1..100); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 27 2007
|
|
|
MATHEMATICA
| lst={}; Do[If[PrimeQ[p=Floor[(Pi/2)^n]], AppendTo[lst, p]], {n, 600}
|
|
|
CROSSREFS
| Cf. A014214, A077547.
Sequence in context: A024764 A024773 A176892 * A101001 A068887 A090708
Adjacent sequences: A109612 A109613 A109614 * A109616 A109617 A109618
|
|
|
KEYWORD
| nonn,more
|
|
|
AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Aug 01 2005
|
|
|
EXTENSIONS
| a(8) from Vincenzo Librandi, Dec 09 2011
|
| |
|
|
