A247515 Numbers k such that 2*floor(sqrt(prime(k))) < floor(2*sqrt(prime(k))).

2, 4, 6, 9, 11, 14, 15, 17, 18, 21, 22, 25, 30, 33, 34, 37, 38, 39, 43, 44, 47, 48, 53, 54, 59, 60, 61, 63, 64, 65, 66, 69, 70, 71, 72, 76, 77, 78, 82, 83, 84, 85, 90, 91, 92, 97, 98, 99, 102, 103, 104, 105, 110, 111, 112, 113, 114, 119, 120, 121, 122, 127

Offset

1,1

Comments

A117767(a(n)) < A247485(a(n)); complement of A247514.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Mathematica

A247515Q[k_]:=With[{r=Sqrt[Prime[k]]}, 2Floor[r]<Floor[2r]];
Select[Range[200], A247515Q] (* Paolo Xausa, Oct 23 2023 *)

Prog

(Haskell)
a247515 n = a247515_list !! (n-1)
a247515_list = filter (\x -> a117767 x < a247485 x) [1..]

Crossrefs

Cf. A117767, A247485, A000196, A000040, A000006, A247514.

Sequence in context: A184627 A203988 A160813 * A186220 A285075 A186316

Adjacent sequences: A247512 A247513 A247514 * A247516 A247517 A247518

Keyword

nonn

Author

Reinhard Zumkeller, Sep 20 2014

Status

approved