Shyam Sunder Gupta
IRSE,
Director(Railways and Metros),
Consulting Engineers Group, Jaipur, India302017
email: guptass@rediffmail.com
http://www.shyamsundergupta.com/
What is New? (Update 15 September, 2019) The page on Fascinating Triangular Numbers updated and enlarged. The page on Rare Numbers updated. CYF NO. 50 Solution by Al Zimmermann, Brian Trial, Emmanuel Vantieghem and Alessandro Casini given. Prime curios
11,13,19,31,107,127,199,373,712,797,919,929,1213,1217,1229,1279,1586,3169,3257,4514,5701,7613,7739,11047,15841,16561,21023,35731,38069,46099,100049, 
Do You Know?The digital root of product of twin primes other than (3,5) is always 8. 
Can You Find?CYF NO. 51 The smallest titanic Sphenic number (i.e. products of 3 distinct primes).email your answer 
Contents
Note: The above topics including many more will be added in due course.

My Contributions in Prime CuriosPrime Curios!  site maintained by G. L. Honaker Jr. and Chris Caldwell

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This page was last updated on 15th September, 2019.
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