A049000 Sum of sigma(j) for 1<=j<10^n, where sigma(j) is the sum of divisors of j.

0, 69, 8082, 820741, 82231803, 8224494757, 822465638000, 82246686892516, 8224670172682646, 822467031614802290, 82246703327412473943, 8224670334073621455209, 822467033422857645316807, 82246703342395510922780776, 8224670334240978188556405240

Offset: 0

Author

Enoch Haga and Jud McCranie

Keywords

• nonn

Comments

The ratio of successive terms approaches 100.

Examples

			For n=1, the sum of sigma(j) for j<10 is 1+3+4+7+6+12+8+15+13=69, so a(1)=69.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 0..36 (calculated from the b-file at A072692)

Crossrefs

Cf. A000203, A046915.

Cf. A072691 (Pi^2/12).

Cf. A072692 (sum for 1<=j<=10^n and other links).

Formula

a(n) = A072692(n) - A046915(n) ~ Pi^2/12 * 10^(2*n). - Amiram Eldar, Feb 16 2020

Extensions

One more term from Rick L. Shepherd, Jul 03 2002

More terms from Amiram Eldar, Feb 16 2020