%I #11 May 14 2019 09:36:57
%S 0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,1,0,1,0,1,0,0,0,
%T 2,0,1,0,2,0,2,0,2,0,0,0,4,0,2,0,1,0,2,0,1,0,0,0,4,0,1,0,3,0,4,0,3,0,
%U 1,0,3,0,2,0,1,0,3,0,4,0,1,0,6,0,4,0,5,0,6,0
%N Number of scalene integer triangles with perimeter n and prime side lengths.
%H R. Zumkeller, <a href="/A070080/a070080.txt">Integer-sided triangles</a>
%F a(n) = A070088(n) - A070092(n).
%F a(n) = Sum_{k=1..floor((n-1)/3)} Sum_{i=k+1..floor((n-k-1)/2)} sign(floor((i+k)/(n-i-k+1))) * A010051(i)_* A010051(k) * A010051(n-i-k). - _Wesley Ivan Hurt_, May 13 2019
%e For n=15 there are A005044(15)=7 integer triangles: [1,7,7], [2,6,7], [3,5,7], [3,6,6], [4,4,7], [4,5,6] and [5,5,5]: three are scalene: [2<6<7], [3<5<7] and [4<5<6], but only one consists of primes, therefore a(15)=1.
%t Table[Sum[Sum[(PrimePi[i] - PrimePi[i - 1]) (PrimePi[k] - PrimePi[k - 1]) (PrimePi[n - i - k] - PrimePi[n - i - k - 1])*Sign[Floor[(i + k)/(n - i - k + 1)]], {i, k + 1, Floor[(n - k - 1)/2]}], {k, Floor[(n - 1)/3]}], {n, 100}] (* _Wesley Ivan Hurt_, May 13 2019 *)
%Y Cf. A070080, A070081, A070082, A070088, A005044, A070092, A070097, A070105, A070114.
%K nonn
%O 1,35
%A _Reinhard Zumkeller_, May 05 2002