A163504 a(n) = abs(n-th prime minus n-th odd nonprime).

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

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