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%I #13 Jan 17 2023 16:11:23
%S 4,15,40,85,168,287,464,693,1000,1419,1920,2561,3332,4215,5248,6477,
%T 7920,9519,11360,13419,15664,18193,20976,24075,27560,31347,35392,
%U 39759,44400,49383,55040,61083,67592,74445,81936,89799,98192,107133,116560
%N a(n) is the sum of all possible pairs of the first n primes.
%C Previous name was "Sums of pairs of primes."
%F a(n) = (n+1)*A007504(n). - _Charlie Neder_, Feb 04 2019
%e List the pairs of the first 3 primes:
%e 2,2
%e 2,3
%e 2,5
%e 3,3
%e 3,5
%e 5,5
%e a(3)=40 because it is the sum of these pairs of primes.
%t Table[Total[Flatten[Union[Sort/@Tuples[Prime[Range[n]],2]]]],{n,40}] (* _Harvey P. Dale_, Jan 17 2023 *)
%Y Cf. A007504 (sum of the first n primes).
%K nonn
%O 1,1
%A _Mats Granvik_, Jul 15 2009
%E Name changed by _Jon E. Schoenfield_, Oct 13 2019