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A144137 Numbers n such that between n^K and (n+1)^K there are no primes, where K = sqrt(2). 2
4, 24, 29, 33, 40, 43, 56, 59, 84, 117, 122, 128, 132, 139, 145, 156, 162, 163, 183, 190, 203, 230, 253, 257, 286, 297, 303, 306, 315, 319, 336, 371, 403, 420, 433, 447, 456, 467, 479, 537, 543, 563, 592, 595, 599, 624, 699, 746, 755, 767, 774, 782, 805, 814 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

T. D. Noe, Table of n, a(n) for n=1..133 (no other n < 10^6)

EXAMPLE

a(1)=4 because in range 4^sqrt(2) = 7.10299... and (4+1)^sqrt(2) = 9.73852... there are no primes (8 and 9 aren't primes).

MATHEMATICA

a = {}; k = Sqrt[2]; Do[If[Length[Select[Range[Ceiling[n^k], Floor[(n + 1)^k]], PrimeQ]] == 0, AppendTo[a, n]], {n, 3000}]; a

Select[Range[850], PrimePi[(#+1)^Sqrt[2]]-PrimePi[#^Sqrt[2]]==0&] (* or *) SequencePosition[PrimePi[Range[850]^Sqrt[2]], {x_, x_}][[All, 1]] (* Harvey P. Dale, Jul 31 2021 *)

CROSSREFS

Cf. A014085, A143898, A143935, A144140.

Sequence in context: A324517 A137980 A348299 * A238222 A180924 A176900

Adjacent sequences:  A144134 A144135 A144136 * A144138 A144139 A144140

KEYWORD

nonn

AUTHOR

Artur Jasinski, Sep 11 2008

STATUS

approved

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Last modified December 1 13:38 EST 2021. Contains 349429 sequences. (Running on oeis4.)