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!)
A074905 a(n) = number of terms in A030229 between prime(n) and prime(n+1). 1

%I #9 May 18 2021 19:20:57

%S 0,0,1,1,0,2,0,2,1,0,3,2,0,1,1,3,0,2,1,0,2,1,3,4,0,0,1,0,1,5,1,2,0,5,

%T 0,1,3,1,0,2,0,3,0,1,0,7,7,1,0,0,2,0,2,2,2,2,0,1,1,0,2,7,1,0,1,7,2,3,

%U 0,0,2,2,1,1,2,1,5,1,2,4,0,2,0,1,0,3,3,1,1,1,4,3,1,2,2,1,6,0,6,4,3,2,2,1,1

%N a(n) = number of terms in A030229 between prime(n) and prime(n+1).

%H Harvey P. Dale, <a href="/A074905/b074905.txt">Table of n, a(n) for n = 1..1000</a>

%e Between prime(6)=13 and prime(7)=17 there are two terms in A030229, namely 14 and 15, so a(6) = 2.

%p readlib(issqr): sstmp := proc(n) local t1,i; t1 := 0; for i from ithprime(n) to ithprime(n+1) do if (issqrfree(i) = 'true' and mobius(i)=1) then t1 := t1+1; fi; od; t1; end: sstmp(200);

%t nt[{a_,b_}]:=Count[MoebiusMu[Range[a+1,b-1]],1]; nt/@Partition[Prime[ Range[ 110]],2,1] (* _Harvey P. Dale_, May 18 2021 *)

%Y Cf. A030229, A061265, A061399.

%K nonn

%O 1,6

%A _Jani Melik_, Sep 30 2002

%E Clarified definition, corrected offset, edited. - _N. J. A. Sloane_, May 18 2021

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 18 06:24 EDT 2024. Contains 371769 sequences. (Running on oeis4.)