a(n) is the least k such that k*Mersenne_prime(n)^2 - 1 and k*Mersenne_prime(n)^2 + 1 are twin primes.

A098817

a(n) is the least k such that k*Mersenne_prime(n)^2 - 1 and k*Mersenne_prime(n)^2 + 1 are twin primes.

Terms

    a(0) =2a(1) =18a(2) =72a(3) =780a(4) =228a(5) =852a(6) =228a(7) =1080a(8) =4020a(9) =25800a(10) =6012a(11) =40332a(12) =713502a(13) =332880a(14) =455892a(15) =6428118a(16) =4142652a(17) =173808

External references