A162867 a(n) is the sum of all possible pairs of the first n primes.

4, 15, 40, 85, 168, 287, 464, 693, 1000, 1419, 1920, 2561, 3332, 4215, 5248, 6477, 7920, 9519, 11360, 13419, 15664, 18193, 20976, 24075, 27560, 31347, 35392, 39759, 44400, 49383, 55040, 61083, 67592, 74445, 81936, 89799, 98192, 107133, 116560

Offset

1,1

Comments

Previous name was "Sums of pairs of primes."

Links

Table of n, a(n) for n=1..39.

Formula

a(n) = (n+1)*A007504(n). - Charlie Neder, Feb 04 2019

Example

List the pairs of the first 3 primes:
  2,2
  2,3
  2,5
  3,3
  3,5
  5,5
a(3)=40 because it is the sum of these pairs of primes.

Mathematica

Table[Total[Flatten[Union[Sort/@Tuples[Prime[Range[n]], 2]]]], {n, 40}] (* Harvey P. Dale, Jan 17 2023 *)

Crossrefs

Cf. A007504 (sum of the first n primes).

Sequence in context: A291555 A336995 A053698 * A336971 A059140 A031164

Adjacent sequences: A162864 A162865 A162866 * A162868 A162869 A162870

Keyword

nonn

Author

Mats Granvik, Jul 15 2009

Extensions

Name changed by Jon E. Schoenfield, Oct 13 2019

Status

approved