|
|
A079592
|
|
Primes for which floor(Pi*x) is prime.
|
|
0
|
|
|
17, 19, 31, 61, 71, 73, 101, 229, 241, 311, 313, 331, 373, 401, 499, 541, 569, 797, 821, 863, 881, 911, 919, 967, 1009, 1051, 1093, 1217, 1249, 1289, 1303, 1427, 1459, 1471, 1583, 1667, 1753, 1811, 1879, 1979, 2011, 2053, 2063, 2153
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
LINKS
|
|
|
EXAMPLE
|
floor(Pi*2)=6, which is not prime.
floor(Pi*3)=9, which is not prime.
floor(Pi*5)=15, which is not prime.
The smallest prime x for which floor(Pi*x) is prime is 17, so a(1)=17. (floor(Pi*17)=53.)
|
|
MATHEMATICA
|
For[i = 1, i < 1000, If[PrimeQ[IntegerPart[Pi*Prime[i]]] == True, Print[Prime[i]]]; i++ ]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|