154553

Appears in sequences

• "Ceiling of hypotenuses": a(n) = ceiling(sqrt(a(n-1)^2 + a(n-2)^2)), a(1)=1, a(2)=3.at n=45A104805
• Numbers k such that k^3 divides 13^(k^2) + 1.at n=4A177813
• Numbers k such that k^2 divides 13^k + 1.at n=4A292338
• a(n) is the least integer k such that 1/(Sum_{j=1..n} 1/phi(k*j)) is an integer.at n=37A341810