login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A038529 n-th prime - n-th composite. 10

%I

%S -2,-3,-3,-2,1,1,3,4,7,11,11,16,19,19,22,27,32,33,37,39,40,45,48,53,

%T 59,62,63,65,65,68,81,83,88,89,98,99,103,108,111,116,121,121,129,130,

%U 133,134,145,155,158,159,161,165,166,175,180,185,189,190,195,197,198,207

%N n-th prime - n-th composite.

%C a(n) = A000040(n) - A002808(n). - _Reinhard Zumkeller_, Apr 30 2014

%H Reinhard Zumkeller, <a href="/A038529/b038529.txt">Table of n, a(n) for n = 1..10000</a>

%t composite[n_Integer] := Block[{k=n+PrimePi[n]+1}, While[k-PrimePi[k]-1 != n, k++]; k]; Table[Prime[n] - composite[n], {n,65}]

%t Module[{nn=300,prs,cmps,len},prs=Prime[Range[PrimePi[nn]]];cmps= Complement[ Range[4,nn],prs];len=Min[Length[prs],Length[cmps]]; #[[1]]- #[[2]]&/@ Thread[{Take[prs,len],Take[cmps,len]}]] (* _Harvey P. Dale_, Jun 18 2015 *)

%o (Haskell)

%o a038529 n = a000040 n - a002808 n -- _Reinhard Zumkeller_, Apr 30 2014

%o (Python)

%o from sympy import prime, composite

%o def A038529(n):

%o return prime(n)-composite(n) # _Chai Wah Wu_, Dec 27 2018

%Y Cf. A038529-A038532.

%Y Cf. A014237, A067563.

%K sign,easy

%O 1,1

%A Vasiliy Danilov (danilovv(AT)usa.net) 1998 Jul

%E Mathematica program corrected by Harvey P. Dale, Aug 08 2011

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 11 15:12 EDT 2020. Contains 336428 sequences. (Running on oeis4.)