140625

Appears in sequences

• Smallest label f(T) given to a rooted tree T with n nodes in Matula-Goebel labeling.at n=22A005517
• a(n) = (10*n + 5)^2.at n=37A017330
• a(n) = (12*n + 3)^2.at n=31A017558
• Numbers of form 5^i*9^j, with i, j >= 0.at n=26A025624
• Numbers k such that sigma(phi(k)) = phi(sigma(k)).at n=27A033632
• Numbers whose prime factors are 3 and 5.at n=30A033849
• Squares expressible as the sum of two positive cubes in at least one way.at n=12A050802
• Numbers k that can be expressed as k = w+x = y*z with w*x = (y+z)^3 where w, x, y, and z are all positive integers.at n=37A057370
• For the numbers k that can be expressed as k = w + x = y*z with w*x = y^3 + z^3 where w, x, y, and z are all positive integers, this sequence gives the corresponding values of w*x.at n=12A057443
• Numbers n such that reciprocal of n terminates with an infinite repetition of digit 1. Multiples of 10 are omitted.at n=3A064560
• Triangle with columns built from certain power sequences.at n=40A067402
• Fifth column of triangle A067402.at n=4A067405
• Numbers k having exactly one divisor d such that in binary representation d and k/d have the same number of 1's as k.at n=19A080026
• Numbers k such that sigma(phi(k)) == phi(sigma(k)) (mod k), that is, A033632(k)/k is an integer.at n=29A092584
• Numbers n that are the hypotenuse of exactly 6 distinct integer-sided right triangles, i.e., n^2 can be written as a sum of two squares in 6 ways.at n=7A097219
• a(n) divides the number formed by concatenating the sum of the digits of a(n) with a(n), by a factor not previously used.at n=12A101171
• "Binary prime squares": squares whose binary expansions, read as decimal expansions, are primes.at n=15A108324
• Triangle, generated from (3^(n-k) * 5^k) table.at n=42A120027
• Numbers with 21 divisors.at n=19A137484
• Odd solutions of phi(sigma(k)) = sigma(phi(k)).at n=6A159939