%I #16 Apr 12 2018 18:17:58

%S 16,24,48,72,120,168,240,288,408,432,552,600,720,768,792,912,960,1080,

%T 1128,1248,1392,1680,1728,1848,2088,2280,2400,2472,2568,2640,3240,

%U 3288,3312,3432,3528,4080,4128,4200,4248,4368,4608,4920,5112,5160,5208,5280

%N Difference between squares of twin prime pairs.

%C Except for the first term 16 = 4^2, a(n) is never a square.

%H Reinhard Zumkeller, <a href="/A111046/b111046.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A006512(n)^2 - A001359(n)^2 = A108604(n) - A108570(n) = 2*A054735(n) = 4*A014574(n) = 8*A040040(n).

%p ZL:=[]:for p from 1 to 1400 do if (isprime(p) and isprime(p+2)) then ZL:=[op(ZL),(((p+2)^2)-p^2)]; fi; od; print(ZL); # _Zerinvary Lajos_, Mar 08 2007

%t Select[Table[Prime[n] + 1, {n, 220}], PrimeQ[ # + 1] &] *4 (* _Ray Chandler_, Oct 12 2005 *)

%t 4+4#&/@Select[Partition[Prime[Range[300]],2,1],#[[2]]-#[[1]]==2&] [[All,1]] (* _Harvey P. Dale_, Apr 12 2018 *)

%o (Haskell)

%o a111046 = (* 2) . a054735 -- _Reinhard Zumkeller_, Feb 10 2015

%Y Cf. A001359, A006512, A014574, A040040, A054735, A108570, A108604.

%K easy,nonn

%O 1,1

%A _Giovanni Teofilatto_, Oct 06 2005

%E Edited and extended by _Ray Chandler_, Oct 12 2005