A065894 Number of composites <= 10^n.

0, 5, 74, 831, 8770, 90407, 921501, 9335420, 94238544, 949152465, 9544947488, 95881945186, 962392087981, 9653934463160, 96795058249197, 970155429577330, 9720761658966074, 97376442842345766, 975260045712259139, 9765942332723655392, 97779180397439081159

Offset: 0

Author

Labos Elemer, Nov 28 2001

Keywords

• nonn

Comments

Also, the order number of 10^n as a composite number.

Examples

			10 is the 5th composite number: 4, 6, 8, 9, 10.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 0..29 (calculated using the b-file at A006880)

Crossrefs

Cf. A002808, A006880, A092871.

Programs

Mathematica

Table[ 10^n- (PrimePi[10^n]) -1, {n, 1, 13} ]

Formula

a(n) = 10^n - 1 - A006880(n). - Max Alekseyev, Aug 15 2013

For n>0, a(n) = A092871(n) + 1.

Extensions

More terms from Robert G. Wilson v, Nov 29 2001

Formula and more terms from Max Alekseyev, Aug 15 2013