221444

Appears in sequences

• Expansion of 1 / ((1-x-x^2-x^3)*(1-x-x^3)).at n=19A103321
• Least number k such that (k*M(n))^2 + k*M(n) - 1 and (k*M(n))^2 + k*M(n) + 1 are twin primes where M(n) is the n-th Mersenne prime.at n=14A121371