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a(n) is the floor of the average distance among first n primes.
2

%I #14 Nov 22 2020 21:09:42

%S 1,2,2,4,5,6,7,9,10,12,13,15,16,18,19,21,23,24,26,27,29,30,32,34,36,

%T 38,39,41,42,44,46,48,50,52,54,56,57,59,61,63,65,67,69,71,72,74,77,79,

%U 81,83,85,86,88,90,92,95,96,98,100,102,104,106,108

%N a(n) is the floor of the average distance among first n primes.

%C Is the limit of a(n)/n finite?

%F a(n) = floor((2/(n*(n-1))*Sum_{j=2..n} Sum_{i=1..j-1} (prime(j) - prime(i))).

%t nmax=64;

%t Table[Total[Flatten[Table[Table[Prime[k] - Prime[j], {j, 1, k - 1}], {k, 2, n}]]]/(n*(n - 1)/2), {n, 2, nmax}]//Floor

%Y Cf. A338869 (Shortest most frequent distance among first n primes).

%K nonn

%O 2,2

%A _Andres Cicuttin_, Nov 19 2020