A050252 - OEIS

A050252

Number of digits in the prime factorization of n (counting terms of the form p^1 as p).

1, 1, 1, 2, 1, 2, 1, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 2, 3, 3, 2, 4, 2, 3, 3, 3, 2, 3, 2, 4, 3, 3, 2, 3, 2, 3, 3, 4, 2, 3, 3, 3, 3, 3, 2, 4, 2, 3, 3, 2, 3, 4, 2, 4, 3, 3, 2, 4, 2, 3, 3, 4, 3, 4, 2, 3, 2, 3, 2, 4, 3, 3, 3, 4, 2, 4, 3, 4, 3, 3, 3, 3, 2, 3, 4, 4, 3, 4

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OFFSET

1,4

COMMENTS

a(A192010(n)) = n and a(m) != n for m < A192010(n);

a(A046759(n))<A055642(A046759(n)); a(A046758(n))=A055642(A046758(n)); a(A046760(n))>A055642(A046760(n)). [Reinhard Zumkeller, Jun 21 2011]

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Prime Factorization.

MATHEMATICA

nd[n_]:=Total@IntegerLength@Select[Flatten@FactorInteger[n], #>1&]; Table[If[n==1, 1, nd[n]], {n, 102}] (* Vladimir Joseph Stephan Orlovsky, Jan 30 2012 *)

PROG

(Haskell)

a050252 1 = 1

a050252 n = sum $ map a055642 $

(a027748_row n) ++ (filter (> 1) $ a124010_row n)

-- Reinhard Zumkeller, Aug 03 2013, Jun 21 2011

CROSSREFS

Cf. A046758, A073048.

Cf. A055642, A020639, A027748, A124010, A110475.

Sequence in context: A097471 A025868 A271721 * A025877 A219182 A184171

Adjacent sequences: A050249 A050250 A050251 * A050253 A050254 A050255

KEYWORD

nonn,base

AUTHOR

Eric W. Weisstein

STATUS

approved