Centered polygonal graceful labeling of some graphs.

If the n^th centered polygonal number is denoted by C_k (n) then C k (n) = k 2 [ n (n − 1 ] + 1 , where k≥3 is the number of sides of the polygon. For k = 3, it gives centered triangular numbers. For k = 4 gives centered tetragonal numbers and so on. In this paper, we introduce the centered polygonal graceful labeling and we prove that the star, subdivision of the star, path, coconut tree, bistar and comb graph are centered polygonal graceful graphs. [ABSTRACT FROM AUTHOR]