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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A109489 Value of Product[k/sd(k,2),k=1..n], where sd(k,b) is the sum of the digits of k represented in base b.

Table of values

n a(n)
1 1
2 2
3 3
4 12
5 30
6 90
7 210
8 1680
9 7560
10 37800
11 138600
12 831600
13 3603600
14 16816800
15 63063000
16 1009008000
17 8576568000
18 77189112000
19 488864376000
20 4888643760000
21 34220506320000
22 250950379680000
23 1442964683160000
24 17315576197920000

List of values

[1, 2, 3, 12, 30, 90, 210, 1680, 7560, 37800, 138600, 831600, 3603600, 16816800, 63063000, 1009008000, 8576568000, 77189112000, 488864376000, 4888643760000, 34220506320000, 250950379680000, 1442964683160000, 17315576197920000]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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