3411409

Appears in sequences

• Member r=14 of the family of Chebyshev sequences S_r(n) defined in A092184.at n=7A098299
• Numbers k that require four iterations of the sigma function to be >= 2*k.at n=29A107914
• Perfect squares which can be written neither as a^2+b^2, nor as a^2+2*b^2, nor as a^2+3*b^2, nor as a^2+7*b^2, with a > 0 and b > 0.at n=19A216408
• Numbers n such that 2n-1 and sigma(n) are both primes.at n=22A249902
• Squares whose second arithmetic derivative is a square.at n=21A348425