Number Recreations

Shyam Sunder Gupta
Indian Railways,
Jaipur, India-302019

What is New? (Update 28 November, 2018)

The page on Amazing Number 108 updated and enlarged.

The page on Fascinating Triangular Numbers updated and enlarged.

The page on Curious Properties of 153 updated and enlarged.

The page on Amicable Numbers updated.

Do You Know?

There can not be three consecutive triangular numbers which can form a Pythagorean triple.

Can You Find?

CYF NO. 50
Three odd positive integers a, b and c such that a+b, b+c and c+a are all Perfect Squares.

email your answer


Note: The above topics including many more will be added in due course.


My Contributions in Prime Curios

Prime Curios! - site maintained by G. L. Honaker Jr. and Chris Caldwell

My Favorite Links

  • Magic Squares,Magic Stars and Other Interesting number patterns by Harvey Heinz
  • Mudd Math Fun Facts pages
  • On-Line Encyclopedia of Integer Sequences OEIS
  • Math Puzzles
    An interesting site with lot of math recreations by Ed Pegg Jr.

My Favorite Books

Recommended list of books for those interested in Recreational and Computational Number theory
In Association with In Association with

The Rail
(January, 2003)

(March, 2003)
The Busy Educator Award
(October, 2003)

Send me e-mail at

This page was last updated on 28th November, 2018.

Copyright 2001-2019 Shyam Sunder Gupta. All rights reserved.