22498

Appears in sequences

• a(n) = prime(n)*prime(n-1) - 1.at n=35A023515
• Product of twin primes minus 1.at n=11A120875
• Constant term of the reduction by x^2->x+1 of the polynomial p(n,x) defined below in Comments.at n=17A192752
• Positive integers m such that none of the four consecutive numbers m, m+1, m+2, m+3 can be written as p^2 + q with p and q both prime.at n=14A258661
• G.f.: Sum_{n>=1} Sum_{k=0..n} binomial(n,k) * x^(k^2) * (x^n - x^k)^(n-k), ignoring the constant term.at n=62A292808
• a(n) = 2*A276086(n) - A276086(A001065(n)), where A276086 is the primorial base exp-function, and A001065 is the sum of proper divisors of n.at n=28A379494