135200

Appears in sequences

• a(n) = n*(2*n+1)^2.at n=32A084367
• a(n) = numerator of Product_{k=1..n} k^mu(n+1-k), where mu(k) = A008683(k).at n=38A130088
• Numbers with prime factorization p^2*q^2*r^5 where p, q, and r are distinct primes.at n=12A190114
• Least integer m > 0 with pi(m*n) = sigma(m), where sigma(m) is the sum of all positive divisors of m.at n=36A247603
• a(n) is the smallest number satisfying a(n)^2+1 = p(n)*q(n), p(n) < q(n) both prime, such that q(n+1)/p(n+1) < q(n)/p(n) with the initial condition q(1)/p(1) < 3/2.at n=15A261803
• Number of 3-cycles in the n X n rook graph.at n=25A288961
• a(n) is the least k such that the average number of nonunitary divisors of {1..k} is >= n.at n=3A344272
• Numbers m such that m^2 + 1 = p*q with p, q primes and m = (p + q)/2 - 1.at n=11A348594
• Expansion of g.f. A(x) satisfying A(x) = A( x^2*(1+x)^6 ) / (x*(1+x)^5).at n=11A369549