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%I #39 Jul 28 2020 20:00:13
%S 2,3,5,7,10,14,15,21,22,25,26,33,34,35,38,39,46,49,51,55,57,58,62,65,
%T 69,74,77,82,85,86,87,91,93,94,95,102,105,110,114,116,117,124,125,130,
%U 138,147,148,153,154,164,165,170,171,172,174,175,182,186,188,190,195
%N Natural numbers n such that the number of prime factors of n (counted with multiplicity) is equal to the number of decimal digits of n.
%H Charles R Greathouse IV, <a href="/A115024/b115024.txt">Table of n, a(n) for n = 1..10000</a>
%e 25 = 5*5 and 25 has two digits.
%e 116 = 2*2*29 and 116 has three digits.
%t Select[Range[2, 300], Sum[FactorInteger[ # ][[i]][[2]], {i, 1, Length[FactorInteger[ # ]]}] == Floor[Log[10, # ] + 1] &] (* _Stefan Steinerberger_, Feb 27 2006 *)
%t Select[Range[200],PrimeOmega[#]==IntegerLength[#]&] (* _Harvey P. Dale_, Jul 28 2020 *)
%o (PARI) is(n)=#Str(n)==bigomega(n) \\ _Charles R Greathouse IV_, Feb 04 2013
%Y Cf. A165256, A167050.
%K base,easy,nonn
%O 1,1
%A _Giovanni Teofilatto_, Feb 24 2006
%E More terms from _Stefan Steinerberger_, Feb 27 2006