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A192319
Numbers k such that the half-open interval (k-5*sqrt(sqrt(k)), k] does not contain primes.
0
1, 1358, 1359, 1360, 31464, 31465, 31466, 31467, 31468
OFFSET
1,2
COMMENTS
a(9) = 31468 is probably the last term. Any further terms must be greater than 1.5 * 10^18. [Charles R Greathouse IV, Jun 27 2011]
MAPLE
isA192319 := proc(n) phigh := n ; plow := ceil(n-5*root[4](n))-1 ; numtheory[pi](phigh)-numtheory[pi](plow) = 0 ; end proc:
for n from 1 do if isA192319(n) then print(n); end if; end do: # R. J. Mathar, Jul 10 2011
PROG
(PARI) isA192319(n)=nextprime(floor(n+1-5*n^.25))>n \\ Charles R Greathouse IV, Jun 27 2011
CROSSREFS
Subsequence of A192320.
Sequence in context: A259249 A215865 A172379 * A125270 A316680 A252379
KEYWORD
nonn,more
AUTHOR
STATUS
approved