A301707 - OEIS

A301707

a(n) = n * Sum_{k prime<=n} k.

0, 4, 15, 20, 50, 60, 119, 136, 153, 170, 308, 336, 533, 574, 615, 656, 986, 1044, 1463, 1540, 1617, 1694, 2300, 2400, 2500, 2600, 2700, 2800, 3741, 3870, 4960, 5120, 5280, 5440, 5600, 5760, 7289, 7486, 7683, 7880, 9758, 9996, 12083, 12364, 12645, 12926, 15416, 15744

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OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = n * A034387(n).

EXAMPLE

a(6) = 6 * Sum_{k primes<=6} = 6 * (2+3+5) = 6 * 10 = 60.

MATHEMATICA

Array[# Sum[Prime@ i, {i, PrimePi@ #}] &, 48] (* Michael De Vlieger, Apr 10 2018 *)

With[{nn=50}, {prs=Prime[Range[PrimePi[nn]]]}, Table[n *Total[Select[prs, #<=n&]], {n, nn}]] (* Harvey P. Dale, Nov 24 2025 *)