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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.

A060273 Hard numbers: a(n) = smallest positive number m with f(m) = n, where f(m) is the smallest number of digits that are needed to construct m using only 1's, 2's and any number of +, -, *, ^ signs, allowing concatenation of the digits.

Table of values

n a(n)
1 1
2 3
3 5
4 7
5 29
6 51
7 151
8 601
9 1631
10 7159
11 19145
12 71515
13 378701

List of values

[1, 3, 5, 7, 29, 51, 151, 601, 1631, 7159, 19145, 71515, 378701]

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

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