79800

Appears in sequences

• 1 / min{1/n - 1/a - 1/b > 0}, where a and b are integers.at n=18A045470
• Triangular numbers which are products of triangular numbers larger than 1.at n=38A068143
• Triangular numbers whose sum of prime factors (with repetition) is also triangular.at n=32A076169
• Triangular numbers which are 8-almost primes.at n=10A076582
• a(n) = n^2 * (n^2 - 1)/2.at n=19A083374
• Triangular numbers > 0 with a prime signature that has not occurred earlier.at n=38A085076
• Numbers that can be expressed as the difference of the squares of primes in exactly eight distinct ways.at n=14A092004
• a(n) = 6 + floor((1 + Sum_{j=1..n-1} a(j))/3).at n=33A120152
• Alexandrian integers: numbers of the form n = p*q*r such that 1/n = 1/p - 1/q - 1/r for some integers p,q,r.at n=37A147811
• Triangular numbers that are the product of two triangular numbers greater than 1.at n=27A188630
• Numbers with prime factorization p*q*r*s^2*t^3 (where p, q, r, s, t are distinct primes).at n=22A190111
• Row sums of the triangle A045975.at n=19A204558
• Triangular numbers k whose divisors can be partitioned into three disjoint sets whose sums are all sigma(k)/3.at n=30A206025
• Number of nX6 0..1 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.at n=8A224036
• Least hexagonal number that is the product of n hexagonal numbers greater than 1.at n=2A225066
• Triangular numbers that are the product of three distinct triangular numbers greater than 1.at n=17A225440
• Triangular numbers that are the product of a triangular number and an oblong number.at n=25A253652
• Triangular numbers k such that psi(k) is a square, where psi(k) is the Dedekind psi function (A001615).at n=26A292064
• Triangular numbers that can be represented as a product of two triangular numbers greater than 1, and as a product of three triangular numbers greater than 1.at n=8A295769
• a(n) = (2*n^2*(n^2 - 3) - (2*n^2 + 1)*(-1)^n + 1)/64.at n=39A302647