Shyam Sunder Gupta
IRSE, FIE, FIPWE,
Former Principal Chief Engineer,
North Western Railway, Jaipur, India302017
email: guptass@rediffmail.com
http://www.shyamsundergupta.com/
What is New? (Update 12 April, 2021) The page on Amicable Numbers updated. The page on Fascinating Triangular Numbers updated. The page on Unlucky 13 updated. CYF NO. 53 Solution by Al Zimmermann and Brian Trial given. CYF NO. 49 Comments by Daniel Suteu given. Prime curios 62,102,181,199,293,373,881,993, 1524,1609,3527,6031,6691,7740,7757,9257,9647 and many more added. 
Do You Know?2^{16} = 65536 is the only known power of 2 in which no digit is a power of 2. 
Can You Find?CYF NO. 54 The smallest number n such that Eulers Trinomial n*n + n + 41 gives a Strong Pseudoprime (base2).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 12th April, 2021.
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