cp's OEIS Frontend

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.

A181581 Smallest k such that each of the five factorials (5k)!, (5k+1)!, (5k+2)!, (5k+3)! and (5k+4)! has exactly 10^n trailing 0's. Zero, if no such k exists.

Table of values

n a(n)
0 1
1 9
2 81
3 801
4 8002
5 80001
6 800001
7 8000002
8 80000003
9 800000003
10 8000000003
11 80000000003
12 800000000002
13 8000000000003
14 80000000000004
15 0
16 0
17 0
18 800000000000000004
19 8000000000000000003
20 0
21 800000000000000000005
22 8000000000000000000006
23 0

List of values

[1, 9, 81, 801, 8002, 80001, 800001, 8000002, 80000003, 800000003, 8000000003, 80000000003, 800000000002, 8000000000003, 80000000000004, 0, 0, 0, 800000000000000004, 8000000000000000003, 0, 800000000000000000005, 8000000000000000000006, 0]

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

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