A054617 a(n) = Sum_{d|n} phi(d)*10^(n/d).

0, 10, 110, 1020, 10120, 100040, 1001220, 10000060, 100010240, 1000002060, 10000100440, 100000000100, 1000001022240, 10000000000120, 100000010000660, 1000000000204080, 10000000100020480, 100000000000000160, 1000000001002002660

Offset: 0

Author

N. J. A. Sloane, Apr 16 2000

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..1000

Crossrefs

Column k=10 of A185651.

Cf. A054629.

Formula

Dirichlet convolution of A000010 and A011557. - R. J. Mathar, Jan 11 2013

a(n) = Sum_{k=1..n} 10^gcd(n,k). - Ilya Gutkovskiy, Apr 16 2021