A109490 Value of Product[k/sd(k,3),k=1..n], where sd[k,b] is the sum of the digits of k represented in base b.

1, 1, 3, 6, 10, 30, 70, 140, 1260, 6300, 23100, 138600, 600600, 2102100, 10510500, 42042000, 142942800, 1286485200, 8147739600, 40738698000, 285170886000, 1568439873000, 7214823415800, 43288940494800, 216444702474000

Offset

1,3

Comments

See A109489 for the corresponding base-2 sequence.

For n=601 the sum is not an integer (its denominator is 7). B-file contains all terms before that.

Links

Robert Israel, Table of n, a(n) for n = 1..600

Maple

P:= 1: A[1]:= P:
for n from 2 to 100 do
  P:= P*n/convert(convert(n, base, 3), `+`);
  A[n]:= P;
od:
seq(A[i], i=1..100); # Robert Israel, Jan 21 2018

Crossrefs

Cf. A109489.

Sequence in context: A068195 A080506 A109163 * A130760 A154134 A001465

Adjacent sequences: A109487 A109488 A109489 * A109491 A109492 A109493

Keyword

nonn,base,easy,fini

Author

John W. Layman, Jun 29 2005

Status

approved