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A184869 Numbers k such that floor[(k-1/2)*(2+2^(1/2))+1/2] is prime.

%I A184869 #10 Jan 30 2018 15:57:11
%S A184869 1,2,6,9,13,16,20,22,29,30,39,44,53,57,67,71,74,80,102,104,108,118,
%T A184869 129,132,136,143,153,159,176,180,190,194,203,211,217,218,227,231,234,
%U A184869 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
%N A184869 Numbers k such that floor[(k-1/2)*(2+2^(1/2))+1/2] is prime.
%H A184869 G. C. Greubel, <a href="/A184869/b184869.txt">Table of n, a(n) for n = 1..10000</a>
%t A184869 a[n_]:=Floor[(n-1/2)*(2+2^(1/2))+1/2];
%t A184869 Table[a[n],{n,1,120}]  (* A063957 *)
%t A184869 t1={}; Do[If[PrimeQ[a[n]], AppendTo[t1,a[n]]],{n,1,600}];t1
%t A184869 t2={}; Do[If[PrimeQ[a[n]], AppendTo[t2,n]],{n,1,600}];t2
%t A184869 t3={}; Do[If[MemberQ[t1,Prime[n]],AppendTo[t3,n]],{n,1,400}];t3
%t A184869 (* Lists t1, t2, t3 match A184868, A184869, A184870. *)
%o A184869 (PARI) isok(k) = isprime(floor((k-1/2)*(2+sqrt(2))+1/2)); \\ _Michel Marcus_, Jan 30 2018
%Y A184869 Cf. A184774, A184868, A184870.
%K A184869 nonn
%O A184869 1,2
%A A184869 _Clark Kimberling_, Jan 23 2011