A Figurate Number of the form
, where is the th Triangular Number. The first few
are 2, 6, 12, 20, 30, 42, 56, 72, 90, 110, ... (Sloane's A002378). The Generating Function of the pronic numbers is

The first few for which are Palindromic are 1, 2, 16, 77, 538, 1621, ... (Sloane's A028336), and the first few Palindromic Numbers which are pronic are 2, 6, 272, 6006, 289982, ... (Sloane's A028337).

**References**

De Geest, P. ``Palindromic Products of Two Consecutive Integers.'' http://www.ping.be/~ping6758/consec.htm.

Sloane, N. J. A. A028336, A028337, and A002378/M1581 in ``An On-Line Version of the Encyclopedia of Integer Sequences.'' http://www.research.att.com/~njas/sequences/eisonline.html.

© 1996-9

1999-05-26