login
A062537
Nodes in riff (rooted index-functional forest) for n.
32
0, 1, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 3, 4, 4, 4, 5, 5, 5, 4, 5, 4, 5, 4, 5, 5, 6, 5, 4, 6, 5, 6, 5, 5, 5, 6, 6, 5, 6, 5, 6, 6, 5, 6, 5, 4, 5, 6, 6, 4, 5, 7, 6, 6, 6, 5, 7, 5, 6, 6, 4, 7, 7, 5, 6, 6, 7, 6, 6, 6, 6, 6, 6, 7, 7, 6, 6, 4, 6, 5, 7, 7, 6, 7, 7, 6, 7, 7, 6, 7, 7, 7, 6, 5, 5, 7, 6, 6, 7, 5, 7, 8
OFFSET
1,3
COMMENTS
A061396(n) is the number of times n appears in this sequence.
FORMULA
a(Product(p_i^e_i)) = Sum(a(i)+a(e_i)+1), product over nonzero e_i in prime factorization.
a(n) = Sum_{k=1..A001221(n)} (a(A049084(A027748(n,k))) + a(A124010(n,k)) + 1). - Reinhard Zumkeller, Feb 26 2013
MATHEMATICA
a[1] = 0; a[n_] := a[n] = Sum[{p, e} = pe; a[PrimePi[p]] + a[e] + 1, {pe, FactorInteger[n]}]; Array[a, 105] (* Jean-François Alcover, Jul 26 2019 *)
PROG
(Haskell)
import Data.Function (on)
a062537 1 = 0
a062537 n = sum $ map (+ 1) $
zipWith ((+) `on` a062537) (map a049084 $ a027748_row n) (a124010_row n)
-- Reinhard Zumkeller, Feb 26 2013
CROSSREFS
KEYWORD
nonn,easy,nice
AUTHOR
David W. Wilson, Jun 25 2001
STATUS
approved