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 A077808 Number of prime factors of numbers containing in their decimal representation only the digits 0 and 1 (counted with multiplicity). 2

%I #12 Aug 31 2018 03:36:34

%S 0,2,1,4,1,3,2,6,3,3,2,5,2,4,2,8,2,5,3,5,4,4,1,7,3,4,4,6,2,4,2,10,2,4,

%T 4,7,3,5,3,7,3,6,2,6,4,3,1,9,3,5,3,6,2,6,2,8,2,4,2,6,2,4,5,12,2,4,2,6,

%U 2,6,2,9,2,5,4,7,2,5,2,9,2,5,3,8,3,4,2,8,1,6,3,5,4,3,4,11,5,5,3,7,1,5

%N Number of prime factors of numbers containing in their decimal representation only the digits 0 and 1 (counted with multiplicity).

%H Vincenzo Librandi, <a href="/A077808/b077808.txt">Table of n, a(n) for n = 1..8190</a>

%F a(n) = A001222(A007088(n)).

%e a(36) = A001222(A007088(36)) = A001222(100100) = A001222(2*2*5*5*7*11*13) = 7.

%t PrimeOmega[#]&/@(Rest[Union[Flatten[Table[FromDigits/@Tuples[ {0,1}, n],{n,7}]]]]) (* _Harvey P. Dale_, May 18 2012 *)

%Y Cf. A077807.

%K nonn,base

%O 1,2

%A _Reinhard Zumkeller_, Nov 16 2002

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Last modified September 19 11:33 EDT 2024. Contains 376010 sequences. (Running on oeis4.)