180318

Appears in sequences

• Numbers k such that k*((2^61-1)^2) - 1 and k*((2^61-1)^2) + 1 are twin primes.at n=26A099229
• a(n) = 1*4*7 + 4*7*10 + 7*10*13 + ... (n terms).at n=12A196513