# Bell triangle

This online calculator constructs the Bell triangle for the given number of rows.

The calculator constructs the Bell triangle for the given number of rows. The values of the triangle elements count partitions of a set in which a given triangle element is the largest singleton1. The rightmost value of each row is the Bell number for a set of size n, where n is a row number, starting from 1. The rightmost value of n-th row is the count of all possible partitions of a set of size n. The construction of the Bell triangle is described below the calculator. Note that this calculator uses the "big integers" library (see Tips and tricks #9: Big numbers), so you can build pretty large triangles. #### Bell triangle

The file is very large. Browser slowdown may occur during loading and creation.

### Construction of the Bell triangle

The number 1 is placed in the first position of the first row.
Row 1: 1

Each next row starts by copying the rightmost value of the previous row.
Row 1: 1
Row 2: 1

The next value in the row is calculated by adding the previous value in the row with the corresponding value from the previous row.
Row 1: 1
Row 2: 1 2(1+1)

Then
Row 1: 1
Row 2: 1 2
Row 3: 2 3(1+2) 5(2+3)

And so on...

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PLANETCALC, Bell triangle