%I #30 Jan 11 2025 19:20:44
%S 0,8,97,994,9995,99994,999993,9999992,99999988,999999987,9999999989,
%T 99999999985,999999999987,9999999999986,99999999999983,
%U 999999999999980,9999999999999980,99999999999999980,999999999999999976,9999999999999999981,99999999999999999974
%N a(n) = 10^n minus its binary weight.
%C Also exponent of highest power of 2 which divides (10^n)!. - _Robert G. Wilson v_, Jan 10 2025
%H Amiram Eldar, <a href="/A218451/b218451.txt">Table of n, a(n) for n = 0..1000</a>
%F a(n) = A011371(10^n) = 10^n - A000120(10^n).
%F a(n) = 10^n - A118738(n).
%F a(n) = A007814(A000142(A011557(n))). - _Robert G. Wilson v_, Jan 10 2025
%e a(2) = 97 because 10^2 = 100, which is 1100100 in binary, having 3 on bits, and 100 - 3 = 97.
%e a(3) = 994 because 10^3 = 1000, which is 1111101000 in binary, having 6 on bits, and 1000 - 6 = 994.
%t Table[10^n - DigitCount[10^n, 2, 1], {n, 0, 19}]
%o (PARI) a(n)=10^n-hammingweight(5^n) \\ _Charles R Greathouse IV_, Oct 28 2012
%Y Cf. A000120, A011371, A118738.
%K nonn,easy,base
%O 0,2
%A _Alonso del Arte_, Oct 28 2012, based on examples for A011371 from _Hieronymus Fischer_, Jun 06 2012.
%E More terms from _Amiram Eldar_, Jul 16 2023