The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A141560 Nonprimes of form (prime(n)-r(n)), where A141468(n)=r(n)=n-th nonprime and prime(n)=n-th prime. 0

%I #16 Feb 19 2021 08:24:31

%S 1,1,4,9,14,15,21,22,25,34,35,40,50,55,62,65,65,68,69,86,91,91,100,

%T 106,111,118,123,124,133,133,135,136,147,158,161,161,164,169,169,177,

%U 182,187,192,200,201,209,222,225,226,246,255,256,259,264,275,280,287,296

%N Nonprimes of form (prime(n)-r(n)), where A141468(n)=r(n)=n-th nonprime and prime(n)=n-th prime.

%t Module[{nn=200,np,len},np=Select[Range[0,nn],!PrimeQ[#]&];len= Length[ np];Select[ #[[1]]-#[[2]]&/@Thread[{Prime[Range[len]],np}],!PrimeQ[ #]&]] (* _Harvey P. Dale_, Oct 15 2020 *)

%Y Cf. A000040, A141468.

%K nonn,less

%O 1,3

%A _Juri-Stepan Gerasimov_, Aug 14 2008

%E Edited, corrected and extended by _Ray Chandler_, Aug 19 2008

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 May 30 08:26 EDT 2024. Contains 372962 sequences. (Running on oeis4.)