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A054617
a(n) = Sum_{d|n} phi(d)*10^(n/d).
3
0, 10, 110, 1020, 10120, 100040, 1001220, 10000060, 100010240, 1000002060, 10000100440, 100000000100, 1000001022240, 10000000000120, 100000010000660, 1000000000204080, 10000000100020480, 100000000000000160, 1000000001002002660
OFFSET
0,2
LINKS
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
CROSSREFS
Column k=10 of A185651.
Cf. A054629.
Sequence in context: A290421 A113705 A283907 * A288982 A289767 A290207
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 16 2000
STATUS
approved