1,1

An n X n 'rhombus' contains (n^2 + (n-1)^2) squares.

Cf. A006506.

Adjacent sequences: A054864 A054865 A054866 this_sequence A054868 A054869 A054870

Sequence in context: A013094 A013063 A012992 this_sequence A015189 A012944 A013099

hard,nonn

Matti De Craene (Matti.DeCraene(AT)rug.ac.be), May 14 2000