This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A086419 #7 Jan 29 2020 04:38:57 %S A086419 0,2,3,4,5,6,6,7,8,8,9,9,10,10,11,11,12,12,12,13,13,14,14,14,15,15,15, %T A086419 16,16,16,17,17,17,18,18,18,18,19,19,19,20,20,20,20,21,21,21,22,21,22, %U A086419 22,22,23,23,23,24,23,24,24,24,25,24,25,25,26,25,26,26,26,27 %N A086419 Sum of all prime factors of 3-smooth numbers. %H A086419 Amiram Eldar, <a href="/A086419/b086419.txt">Table of n, a(n) for n = 1..10000</a> %F A086419 a(n) = A001414(A003586(n)). %F A086419 a(n) = 2*A022328(n) + 3*A022329(n). %t A086419 s = {}; m = 12; Do[n = 3^k; While[n <= 3^m, AppendTo[s, n]; n*=2], {k, 0, m}]; sopfr[1] = 0; sopfr[n_] := Plus @@ Times @@@ FactorInteger[n]; sopfr /@ Union[s] (* _Amiram Eldar_, Jan 29 2020 *) %Y A086419 Cf. A001414, A003586, A022328, A022329, A086418, A086417, A069352. %K A086419 nonn %O A086419 1,2 %A A086419 _Reinhard Zumkeller_, Jul 18 2003