A Shantha prime is a prime number of the form with being a Mangammal prime (http://planetmath.org/MangammalPrime). The smallest Shantha prime is . The next is and has 259 digits. Shantha primes are very rare among the smaller numbers. The above formulation generates mostly composite numbers.
- 1 A. K. Devaraj, ”Euler’s Generalization of Fermat’s Theorem-A Further Generalization”, in Proceedings of Hawaii International Conference on Statistics, Mathematics & Related Fields, 2004.