OFFSET
1,4
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
FORMULA
Asymptotic mean: lim_{m->oo} (1/m) * Sum_{k=1..m} a(k) = 3/2. - Amiram Eldar, Jan 16 2022
MAPLE
A169611 := proc(n) local f; a := 0 ; for f in ifactors(n)[2] do if op(1, f) <= 3 then a := a+op(2, f) ; end if; end do: return a; end proc: seq(A169611(n), n=1..100) ; # R. J. Mathar, Dec 04 2009
MATHEMATICA
f[n_] := Plus @@ Last /@ Select[ FactorInteger@ n, 1 < #[[1]] < 4 &]; Array[f, 105] (* Robert G. Wilson v, Dec 19 2009 *)
PROG
(PARI) A169611(n)=valuation(n, 2)+valuation(n, 3) \\ M. F. Hasler, Aug 24 2012
(Haskell)
a169611 = a001222 . a065331 -- Reinhard Zumkeller, Nov 19 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Dec 03 2009
EXTENSIONS
Definition corrected by M. F. Hasler, Aug 24 2012
STATUS
approved