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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.

A300000 The sum of the first n terms of the sequence is the concatenation of the first n digits of the sequence, with a(1) = 1.

Table of values

n a(n)
1 1
2 10
3 99
4 999
5 9990
6 99900
7 999000
8 9990000
9 99900000
10 999000000
11 9990000000
12 99899999991
13 998999999919
14 9989999999190
15 99899999991900
16 998999999918991
17 9989999999189910
18 99899999991899109
19 998999999918991090
20 9989999999189910900
21 99899999991899108991
22 998999999918991089910
23 9989999999189910899100

List of values

[1, 10, 99, 999, 9990, 99900, 999000, 9990000, 99900000, 999000000, 9990000000, 99899999991, 998999999919, 9989999999190, 99899999991900, 998999999918991, 9989999999189910, 99899999991899109, 998999999918991090, 9989999999189910900, 99899999991899108991, 998999999918991089910, 9989999999189910899100]

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

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