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!)
A163504 a(n) = abs(n-th prime minus n-th odd nonprime). 1
1, 6, 10, 14, 14, 14, 16, 16, 16, 16, 18, 14, 14, 14, 16, 12, 10, 14, 10, 10, 12, 8, 8, 4, 2, 2, 2, 4, 6, 4, 8, 10, 14, 14, 20, 18, 22, 22, 24, 28, 32, 28, 36, 34, 36, 34, 42, 52, 52, 52, 50, 54, 54, 62, 62, 62, 66, 66, 70, 72, 70, 78, 90, 92, 92, 92, 100, 102, 110, 106, 108, 112 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = abs(A000040(n)-A014076(n)).

EXAMPLE

a(1)=abs(2-1)=1; a(2)=abs(3-9)=6.

MAPLE

A014076 := proc(n) option remember; local a; if n = 1 then 1; else for a from procname(n-1)+2 by 2 do if not isprime(a) then return a; end if; end do: end if; end proc: A163504 := proc(n) abs(ithprime(n)-A014076(n)) ; end: seq(A163504(n), n=1..80) ; # R. J. Mathar, Oct 10 2009

MATHEMATICA

A014076 := Select[Range[1, 10000, 2], PrimeOmega[#] != 1 &]; Table[Abs[Prime[n] - A014076[[n]]], {n, 1, 50}] (* G. C. Greubel, Jul 27 2017 *)

CROSSREFS

Cf. A000040, A014076, A129146.

Sequence in context: A163814 A088706 A087710 * A129146 A315158 A315159

Adjacent sequences:  A163501 A163502 A163503 * A163505 A163506 A163507

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Jul 29 2009

EXTENSIONS

An 8 inserted by R. J. Mathar, Oct 10 2009

STATUS

approved

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 June 16 04:13 EDT 2021. Contains 345055 sequences. (Running on oeis4.)