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A116671
Primes p such that the nearest integer to p * Pi is prime.
2
13, 17, 31, 53, 71, 73, 101, 181, 197, 223, 229, 239, 241, 281, 311, 313, 353, 367, 491, 521, 607, 821, 859, 863, 919, 1129, 1217, 1303, 1381, 1427, 1471, 1583, 1667, 1721, 1723, 1753, 1811, 1877, 1879, 1933, 1979, 2017, 2063, 2089, 2221, 2399, 2441, 2447
OFFSET
1,1
LINKS
EXAMPLE
floor (13Pi + .5) = 41.
floor (17Pi + .5) = 53.
MATHEMATICA
lst={}; Do[p=Prime[n]; If[PrimeQ[Round[p*Pi]], AppendTo[lst, p]], {n, 10^3}]; lst
Select[Prime[Range[400]], PrimeQ[Round[# Pi]]&] (* Harvey P. Dale, Mar 02 2024 *)
CROSSREFS
Sequence in context: A083983 A129338 A138535 * A062338 A143863 A158571
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Edited by Charles R Greathouse IV, Nov 11 2009
STATUS
approved