A086418 Sum of distinct prime factors of 3-smooth numbers.

0, 2, 3, 2, 5, 2, 3, 5, 2, 5, 5, 3, 2, 5, 5, 5, 2, 5, 3, 5, 5, 2, 5, 5, 5, 5, 3, 2, 5, 5, 5, 5, 5, 2, 5, 5, 3, 5, 5, 5, 2, 5, 5, 5, 5, 5, 5, 2, 3, 5, 5, 5, 5, 5, 5, 2, 5, 5, 5, 5, 5, 3, 5, 5, 2, 5, 5, 5, 5, 5, 5, 5, 5, 2, 5, 5, 3, 5, 5, 5, 5, 5, 5, 2, 5, 5, 5, 5, 5, 5, 5, 5, 3, 5, 2, 5, 5, 5, 5, 5, 5, 5

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = A008472(A003586(n));

a(n) = 2*0^(0^A022328(n)) + 3*0^(0^A022329(n)).

Mathematica

s = {}; m = 12; Do[n = 3^k; While[n <= 3^m, AppendTo[s, n]; n*=2], {k, 0, m}]; sopf[1] = 0; sopf[n_] := Plus @@ First@Transpose @ FactorInteger[n]; sopf /@ Union[s] (* Amiram Eldar, Jan 29 2020 *)

Crossrefs

Cf. A003586, A008472, A022328, A022329, A086419, A086417, A086412.

Sequence in context: A260218 A087986 A129088 * A100761 A336964 A027748

Adjacent sequences: A086415 A086416 A086417 * A086419 A086420 A086421

Keyword

nonn

Author

Reinhard Zumkeller, Jul 18 2003

Status

approved