58860

Appears in sequences

• Numbers k such that 2k+1, 4k+1, 6k+1 and 8k+1 are primes.at n=30A124409
• G.f.: A(x) = (A_1)^3 where A_1 = 1 + x*(A_2)^3; A_2 = 1 + x^2*(A_3)^3; A_3 = 1 + x^3*(A_4)^3; ... A_n = 1 + x^n*(A_{n+1})^3 for n>=1.at n=19A132331
• Exponential (2,4)-perfect numbers: numbers m such that esigma(esigma(m)) = 4m, where esigma(m) is the sum of exponential divisors of m (A051377).at n=28A328133