A275626 Denominator of Sum_{k=1..n} 0.k.

10, 10, 5, 1, 2, 10, 5, 5, 2, 5, 100, 100, 25, 10, 4, 100, 50, 25, 20, 20, 25, 50, 100, 20, 10, 25, 100, 100, 5, 10, 100, 100, 50, 1, 20, 100, 25, 50, 20, 4, 50, 25, 100, 20, 5, 50, 100, 100, 10, 5, 100, 100, 25, 10, 20, 100, 50, 25, 4, 20, 25, 50, 100, 20, 2, 25, 100, 100, 5, 10, 100, 100, 50

Offset

1,1

Comments

Here 0.k means the decimal fraction obtained by writing k after the decimal point, e.g. 0.12 = 12/100 = 3/25.

Links

Alois P. Heinz, Table of n, a(n) for n = 1..20000

Example

The first few values of Sum{k=1..n} 0.k are:
1/10, 3/10, 3/5, 1, 3/2, 21/10, 14/5, 18/5, 9/2, 23/5, 471/100, 483/100, 124/25, 51/10, 21/4, 541/100, 279/50, 144/25, 119/20, 123/20, 159/25, 329/50, 681/100, 141/20, 73/10, 189/25, ...

Maple

b:= proc(n) option remember;
       n/10^length(n)+`if`(n<2, 0, b(n-1))
    end:
a:= n-> denom(b(n)):
seq(a(n), n=1..100);  # Alois P. Heinz, Aug 16 2016

Crossrefs

Cf. A275626, A054464 (when a(n) = 1), A275623, A275624.

Sequence in context: A228245 A034078 A180011 * A071531 A276467 A112120

Adjacent sequences: A275623 A275624 A275625 * A275627 A275628 A275629

Keyword

nonn,base,frac

Author

N. J. A. Sloane, Aug 07 2016

Status

approved