A218451 a(n) = 10^n minus its binary weight.

0, 8, 97, 994, 9995, 99994, 999993, 9999992, 99999988, 999999987, 9999999989, 99999999985, 999999999987, 9999999999986, 99999999999983, 999999999999980, 9999999999999980, 99999999999999980, 999999999999999976, 9999999999999999981, 99999999999999999974

Offset

0,2

Comments

Also exponent of highest power of 2 which divides (10^n)!. - Robert G. Wilson v, Jan 10 2025

Links

Amiram Eldar, Table of n, a(n) for n = 0..1000

Formula

a(n) = A011371(10^n) = 10^n - A000120(10^n).

a(n) = 10^n - A118738(n).

a(n) = A007814(A000142(A011557(n))). - Robert G. Wilson v, Jan 10 2025

Example

a(2) = 97 because 10^2 = 100, which is 1100100 in binary, having 3 on bits, and 100 - 3 = 97.
a(3) = 994 because 10^3 = 1000, which is 1111101000 in binary, having 6 on bits, and 1000 - 6 = 994.

Mathematica

Table[10^n - DigitCount[10^n, 2, 1], {n, 0, 19}]

Prog

(PARI) a(n)=10^n-hammingweight(5^n) \\ Charles R Greathouse IV, Oct 28 2012

Crossrefs

Cf. A000120, A011371, A118738.

Sequence in context: A367352 A318012 A320398 * A262777 A367493 A365845

Adjacent sequences: A218448 A218449 A218450 * A218452 A218453 A218454

Keyword

nonn,easy,base

Author

Alonso del Arte, Oct 28 2012, based on examples for A011371 from Hieronymus Fischer, Jun 06 2012.

Extensions

More terms from Amiram Eldar, Jul 16 2023

Status

approved