161190

Appears in sequences

• G.f.: 1/(1-x) = Sum_{n>=0} a(n)*x^n / Product_{k=1..n} (1 + n*k*x).at n=6A201007
• Let p = prime(n). Smallest j such that q = j*2*p^3-1, r = j*p*2*q^2-1, s = j*p*2*r^2-1, and j*p*2*s^2-1 are prime numbers.at n=26A224612