A109941 Sum of all n-digit multiples of n.

45, 2430, 165150, 12370500, 989955000, 82499850000, 7071428928571, 618749955000000, 55000000350000000, 4949999995500000000, 449999999955000000000, 41250000000150000000000, 3807692307689192307692307, 353571428571466428571428572, 32999999999999850000000000000

Offset

1,1

Links

Table of n, a(n) for n=1..15.

Example

a(2) = 2430, a(2) = 10 +12+...+96+98 = 45*(10+98)/2.

Mathematica

Table[Sum[i, {i, n*Ceiling[(10^(n - 1))/n], 10^n - 1, n}], {n, 15}] (* Hans Havermann *)

Crossrefs

Sequence in context: A342405 A279439 A251443 * A035097 A184286 A130017

Adjacent sequences: A109938 A109939 A109940 * A109942 A109943 A109944

Keyword

base,nonn

Author

Amarnath Murthy, Jul 19 2005

Extensions

More terms from Hans Havermann, Jul 22 2005

Status

approved