|
%I #6 May 02 2018 10:18:54
%S 0,0,0,8,10,12,28,16,54,20,66,24,104,28,150,32,170,36,228,40,294,44,
%T 322,48,400,52,432,56,464,60,558,64,660,68,700,72,740,76,858,80,902,
%U 84,1032,88,1170,92,1222,96,1372,100,1428,104,1484,108,1650,112,1710
%N Sum of the perimeters of the family of rectangles with dimensions p and q such that |q - p| is prime, n = p + q and p < q.
%H <a href="/index/Par#part">Index entries for sequences related to partitions</a>
%F a(n) = 2n * Sum_{i=1..floor((n-1)/2)} A010051(n-2i).
%t Table[2 n*Sum[(PrimePi[n - 2 i] - PrimePi[n - 2 i - 1]), {i, Floor[(n - 1)/2]}], {n, 80}]
%o (PARI) a(n) = 2*n*sum(i=1, (n-1)\2, isprime(n-2*i)); \\ _Michel Marcus_, Apr 21 2018
%Y Cf. A010051, A294247.
%K nonn,easy
%O 1,4
%A _Wesley Ivan Hurt_, Apr 19 2018
|
