|
|
A330426
|
|
Primes P where the distance to the nearest prime is greater than 2*log(P).
|
|
4
|
|
|
211, 2179, 2503, 3967, 4177, 7369, 7393, 11027, 11657, 14107, 16033, 16787, 18013, 18617, 18637, 18839, 19661, 21247, 23719, 24281, 29101, 32749, 33247, 33679, 33997, 37747, 38501, 40063, 40387, 42533, 42611, 44417, 46957, 51109, 51383, 53479, 54217, 55291, 55763
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
The author suggests that these numbers be called Double Frogger Primes because two times the distance as the average distance to the nearest neighbor (the log) has to be hopped.
|
|
LINKS
|
|
|
EXAMPLE
|
P = 211 is a term because 199 + 2*log(211) < 211 < 223 - 2*log(211).
P = 199 is not a term because 197 + 2*log(199) > 199.
|
|
MAPLE
|
q:= 3: state:= false: count:= 0: Res:= NULL:
while count < 100 do
p:= nextprime(q);
newstate:= is(p-q > 2*log(q));
if state and newstate then
count:= count+1; Res:= Res, q;
fi;
q:= p; state:= newstate;
od:
|
|
MATHEMATICA
|
lst={}; Do[a=Prime[n]; If[Min[Abs[a-NextPrime[a, {-1, 1}]]]>2*Log[a], AppendTo[lst, a]], {n, 1, 10000}]; lst (* Metin Sariyar, Dec 15 2019 *)
(* Second program: *)
Select[Prime@ Range[10^4], Min@ Abs[# - NextPrime[#, {-1, 1}]] > 2 Log[#] &] (* Michael De Vlieger, Dec 15 2019 *)
|
|
PROG
|
(Magma) f:=func<p|Abs(p-NextPrime(p)) gt 2*Log(p) and Abs(p-PreviousPrime(p)) gt 2*Log(p)>; [p:p in PrimesUpTo(56000)|f(p)]; // Marius A. Burtea, Dec 18 2019
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|