login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A184816 Numbers m such that prime(m) is of the form k+floor(kr/s)+floor(kt/s), where r=sqrt(2), s=sqrt(3), t=sqrt(5). 4

%I #11 Apr 25 2023 14:54:46

%S 1,3,7,14,18,19,21,23,24,26,34,37,39,40,41,50,53,54,55,56,65,68,69,72,

%T 78,80,81,83,86,93,95,96,98,105,106,109,113,117,124,126,129,131,133,

%U 135,137,139,143,145,148,152,157,158,159,160,161,162,168,169,172,173,174,176,183,187,190,197,200,207,208,212,214,219,229,232,234,238,242,243,245,246,257,258,259,266,267,268,270,275,276,278,279,280,281,284

%N Numbers m such that prime(m) is of the form k+floor(kr/s)+floor(kt/s), where r=sqrt(2), s=sqrt(3), t=sqrt(5).

%C See A184812 and A184815.

%H G. C. Greubel, <a href="/A184816/b184816.txt">Table of n, a(n) for n = 1..5000</a>

%t r=2^(1/2); s=3^(1/2); t=5^(1/2);

%t a[n_]:=n+Floor[n*s/r]+Floor[n*t/r];

%t b[n_]:=n+Floor[n*r/s]+Floor[n*t/s];

%t c[n_]:=n+Floor[n*r/t]+Floor[n*s/t]

%t Table[a[n],{n,1,120}] (* A184812 *)

%t Table[b[n],{n,1,120}] (* A184813 *)

%t Table[c[n],{n,1,120}] (* A184814 *)

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

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

%t t3={};Do[If[MemberQ[t1,Prime[n]],AppendTo[t3,n]],{n,1,600}];t3

%t t4={};Do[If[PrimeQ[b[n]], AppendTo[t4,b[n]]],{n,1,600}];t4;

%t t5={};Do[If[PrimeQ[b[n]], AppendTo[t5,n]],{n,1,600}];t5;

%t t6={};Do[If[MemberQ[t4,Prime[n]],AppendTo[t6,n]],{n,1,600}];t6

%t t7={};Do[If[PrimeQ[c[n]], AppendTo[t7,c[n]]],{n,1,600}];t7;

%t t8={};Do[If[PrimeQ[c[n]], AppendTo[t8,n]],{n,1,600}];t8;

%t t9={};Do[If[MemberQ[t7,Prime[n]],AppendTo[t9,n]],{n,1,600}];t9

%t (* Lists t3, t6, t9 match A184815, A184816, A184817. *)

%t PrimePi/@Select[Table[k+Floor[(k Sqrt[2])/Sqrt[3]]+Floor[(k Sqrt[5])/Sqrt[3]],{k,600}],PrimeQ] (* _Harvey P. Dale_, Apr 25 2023 *)

%Y Cf. A184812, A184815, A184817.

%K nonn

%O 1,2

%A _Clark Kimberling_, Jan 23 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 23 22:36 EDT 2024. Contains 371917 sequences. (Running on oeis4.)