A Centered Polygonal Number consisting of a central dot with four dots around it, and then additional dots in the gaps
between adjacent dots. The general term is , and the first few such numbers are 1, 5, 13, 25, 41, ...
(Sloane's A001844). Centered square numbers are the sum of two consecutive Square Numbers and are
congruent to 1 (mod 4). The Generating Function giving the centered square numbers is

**References**

Conway, J. H. and Guy, R. K. *The Book of Numbers.* New York: Springer-Verlag, p. 41, 1996.

Sloane, N. J. A. Sequence
A001844/M3826
in ``An On-Line Version of the Encyclopedia of Integer Sequences.''
http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S.
*The Encyclopedia of Integer Sequences.* San Diego: Academic Press, 1995.

© 1996-9

1999-05-26