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A184869 Numbers k such that floor[(k-1/2)*(2+2^(1/2))+1/2] is prime. 3
1, 2, 6, 9, 13, 16, 20, 22, 29, 30, 39, 44, 53, 57, 67, 71, 74, 80, 102, 104, 108, 118, 129, 132, 136, 143, 153, 159, 176, 180, 190, 194, 203, 211, 217, 218, 227, 231, 234, 238, 241, 252, 259, 275, 276, 278, 285, 296, 299, 303, 319, 320, 341, 350, 357, 361, 375, 378, 382, 399, 401, 405, 419, 422, 426, 435, 436, 443, 449, 457, 463, 473, 477, 480, 498, 501, 508, 514, 521, 524, 528, 531, 549, 559, 566, 572, 580, 586 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..10000

MATHEMATICA

a[n_]:=Floor[(n-1/2)*(2+2^(1/2))+1/2];

Table[a[n], {n, 1, 120}]  (* A063957 *)

t1={}; Do[If[PrimeQ[a[n]], AppendTo[t1, a[n]]], {n, 1, 600}]; t1

t2={}; Do[If[PrimeQ[a[n]], AppendTo[t2, n]], {n, 1, 600}]; t2

t3={}; Do[If[MemberQ[t1, Prime[n]], AppendTo[t3, n]], {n, 1, 400}]; t3

(* Lists t1, t2, t3 match A184868, A184869, A184870. *)

PROG

(PARI) isok(k) = isprime(floor((k-1/2)*(2+sqrt(2))+1/2)); \\ Michel Marcus, Jan 30 2018

CROSSREFS

Cf. A184774, A184868, A184870.

Sequence in context: A184621 A184821 A292659 * A047276 A171639 A054770

Adjacent sequences:  A184866 A184867 A184868 * A184870 A184871 A184872

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jan 23 2011

STATUS

approved

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Last modified April 11 00:03 EDT 2021. Contains 342877 sequences. (Running on oeis4.)