62100

Appears in sequences

• a(n) = 225*(n-1)*(n-2)/2.at n=22A027470
• Decimal part of cube root of a(n) starts with 6: first term of runs.at n=37A034132
• a(n) = 18n^3 + 6n^2.at n=15A087887
• Smaller member of an infinitary amicable pair.at n=13A126169
• Infinitary amicable numbers.at n=25A127664
• a(n) = (9/2)*(n-1)*(n-2)*(n-3).at n=25A134171
• Numbers with prime factorization p*q^2*r^2*s^3 (where p, q, r, s are distinct primes).at n=27A190109
• Integers n such that n^2 becomes another square under the map 8<=>9 (acting on the decimal digits).at n=6A232422
• Numbers of the form Bell(i)*Bell(j).at n=31A276281
• Smaller of bi-unitary amicable pair.at n=16A292980
• Lesser of tri-unitary amicable numbers pair: numbers (m, n) such that tsigma(m) = tsigma(n) = m + n, where tsigma(n) is the sum of the tri-unitary divisors of n (A324706).at n=10A324708
• Column 2 of triangle A354650: a(n) = A354650(n,2), for n >= 1.at n=7A354655
• Ordered product of the terms in a primitive Pythagorean quadruple (with repetitions).at n=38A367737
• a(n) = Sum_{k=1..n} Sum_{z=1..n} Sum_{y=1..n} Sum_{x=1..n} [GCD(f(x,y,z), n) = k] * f(x,y,z) * A023900(k), where f(x,y,z) = x^2 + y^2 - z^2.at n=14A373582
• a(n) is the smallest nonnegative integer k where exactly n pairs of positive integers (x, y) exist such that x^2 + 11*y^2 = k.at n=12A374160