A173386 The absolute values of n-th natural noncomposite number minus n-th number k such that 6*k-+1 is a twin prime pair.

0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 4, 1, 5, 8, 5, 7, 8, 12, 9, 9, 1, 1, 2, 4, 6, 3, 2, 4, 3, 26, 24, 11, 12, 10, 31, 23, 24, 20, 19, 25, 32, 34, 34, 26, 27, 41, 43, 36, 25, 41, 41, 45, 44, 46, 47, 55, 50, 53, 54, 56, 57, 64, 55, 45, 44, 44, 56, 47, 48, 43, 48, 72, 73, 76, 75, 73, 72, 76, 70

Offset

1,11

Links

Table of n, a(n) for n=1..79.

Formula

a(n) = abs(A008578(n) - A002822(n)).

Maple

Contribution from R. J. Mathar, Mar 09 2010: (Start)
A008578 := proc(n) if n= 1 then 1; else ithprime(n-1) ; end if; end proc:
A002822 := proc(n) if n = 1 then 1; else for a from procname(n-1)+1 do if isprime(6*a-1) and isprime(6*a+1) then return a; fi; end do ; end if; end proc:
A173386 := proc(n) abs(A008578(n)-A002822(n)) ; end proc:
seq(A173386(n), n=1..90) ; (End)

Crossrefs

Cf. A002822, A008578.

Sequence in context: A356124 A272534 A332522 * A011443 A016687 A139356

Adjacent sequences: A173383 A173384 A173385 * A173387 A173388 A173389

Keyword

nonn

Author

Juri-Stepan Gerasimov, Feb 17 2010

Status

approved