Logo

A026820 formatted as a triangular array:

1
1 2
1 2 3
1 3 4 5
1 3 5 6 7
1 4 7 9 10 11
1 4 8 11 13 14 15
1 5 10 15 18 20 21 22
1 5 12 18 23 26 28 29 30
1 6 14 23 30 35 38 40 41 42
1 6 16 27 37 44 49 52 54 55 56

A026820 formatted as a square array:

1 1 1 1 1 1 1 1 1 1 1
2 2 3 3 4 4 5 5 6 6
3 4 5 7 8 10 12 14 16
5 6 9 11 15 18 23 27
7 10 13 18 23 30 37
11 14 20 26 35 44
15 21 28 38 49
22 29 40 52
30 41 54
42 55
56

A026820 formatted as an upper right triangle:

1 1 1 1 1 1 1 1 1 1 1
2 2 3 3 4 4 5 5 6 6
3 4 5 7 8 10 12 14 16
5 6 9 11 15 18 23 27
7 10 13 18 23 30 37
11 14 20 26 35 44
15 21 28 38 49
22 29 40 52
30 41 54
42 55
56

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 2 11:54 EST 2009. Contains 167921 sequences.

AT&T Labs Research

Legal Notice
© 2009 AT&T Intellectual Property. All Rights Reserved.