1927561217

Appears in sequences

• Primes of the form 2^r*7^s + 1.at n=27A077498
• Primes p such that sigma((p-1)/2) + tau((p-1)/2) is prime.at n=7A272061
• Lesser of twin primes p such that sigma((p-1)/2) + tau((p-1)/2) is a prime.at n=4A358342