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A168343 n-th single or isolated number minus n. 1
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 (list; graph; refs; listen; history; text; internal format)
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 A236169 A080478

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

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Last modified June 15 19:34 EDT 2019. Contains 324144 sequences. (Running on oeis4.)