A000096

[Antreas P. Hatzipolakis]

ID Number: A000096 (Formerly M1356 and N0522)
Sequence:  0,2,5,9,14,20,27,35,44,54,65,77,90,104,119,135,152,170,189,
           209,230,252,275,299,324,350,377,405,434,464,495,527,560,594,
           629,665,702,740,779
Name:      n(n+3)/2.
Comments:  Comment from Robert G. Wilson v (rgwv at southwind.net): for n>=1,
           a(n) = maximal number of pieces that can be obtained by cutting an
           annulus with n cuts.


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                   n(n-3)
The formula d_n = -------,  n = 3,4,5,6,7,....
                     2

gives the number of diagonals of a n-gon.



Antreas