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
