A168343 n-th single or isolated number minus n.

1, 2, 3, 8, 13, 17, 23, 29, 33, 37, 42, 48, 54, 58, 64, 67, 72, 79, 83, 88, 92, 105, 108, 114, 125, 131, 136, 139, 144, 150, 161, 166, 178, 189, 193, 197, 203, 213, 218, 223, 229, 235, 239, 249, 262, 266, 270, 283, 288, 298, 302, 307, 314, 319, 324, 327, 332, 339

Offset

1,2

Links

Table of n, a(n) for n=1..58.

Formula

a(n) = A167706(n) - A000027(n) = A167706(n) - n.

Maple

isA007510 := proc(n) if isprime(n) then not isprime(n+2) and not isprime(n-2) ; else false; end if; end proc: isA014574 := proc(n) if not isprime(n) then isprime(n+1) and isprime(n-1) ; else false; end if; end proc: A167706 := proc(n) if n = 1 then 2; else for a from procname(n-1)+1 do if isA007510(a) or isA014574(a) then return(a) ; end if; end do ; end if; end proc: A168343 := proc(n) A167706(n)-n ; end proc: seq(A168343(n), n=1..80) ; # R. J. Mathar, Nov 24 2009

Crossrefs

Sequence in context: A160610 A127484 A193882 * A217330 A358207 A236169

Adjacent sequences: A168340 A168341 A168342 * A168344 A168345 A168346

Keyword

nonn

Author

Juri-Stepan Gerasimov, Nov 23 2009

Extensions

Corrected by R. J. Mathar, Nov 24 2009

Status

approved