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%I #11 Sep 29 2015 10:22:48
%S 2,2,4,4,4,2,4,4,4,2,4,4,4,6,6,6,6,6,2,6,6,6,6,6,4,4,4,2,4,4,4,6,6,6,
%T 6,6,6,6,6,6,6,2,6,6,6,6,6,4,4,4,2,6,6,6,6,6,4,4,4,6,6,6,6,6,8,8,8,8,
%U 8,8,8,4,4,4,2,4,4,4,2,4,4,4,14,14,14,14,14,14,14,14,14,14,14,14,14,4,4,4,6
%N Differences of straddle primes.
%F Straddle primes are the nearest primes preceding and following composite n.
%e The first straddle prime pair is 3 and 5 which straddles the composite number 4 and 5-3 = 2 the first entry in the table.
%t NextPrime[#]-NextPrime[#,-1]&/@Rest[Select[Range[200],!PrimeQ[#]&]] (* _Harvey P. Dale_, Aug 23 2012 *)
%o (PARI) straddiff(n) = { local (x,y, pp,np); for(x=1,n, y=composite(x); pp=precprime(y); np=nextprime(y); print1(np-pp",") )
%o composite(n) = { local(c,x); c=1; x=1; while(c <= n, x++; if(!isprime(x),c++); ); return(x) } }
%K easy,nonn
%O 4,1
%A _Cino Hilliard_, Mar 13 2005
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