1587600

Appears in sequences

• Fermionic string states.at n=26A005309
• a(n) = n!*(n-1)!/2^(n-1).at n=7A006472
• Triangle of coefficients from fractional iteration of e^x - 1.at n=27A008826
• Denominators of poly-Bernoulli numbers B_n^(k) with k=4.at n=9A027648
• Sets record for f(n) = |{(a,b):a*b=n and a|b}|. Also squares of highly composite numbers A002182.at n=15A046952
• Least number whose number of divisors is n-th term from A014613 (numbers of form p*q*r*s, products of exactly 4 primes, counted with multiplicity).at n=28A061218
• Smallest number with exactly n^2 divisors.at n=14A061707
• Numbers whose sum of non-unitary divisors is a prime and sets a new record for such primes.at n=32A063760
• Numbers k such that sigma(k) - usigma(k) > 3k.at n=2A063875
• In the following square array A(i,j) = Least Common Multiple of i and j. Sequence contains the product of the terms of the n-th antidiagonal.at n=7A082022
• Coefficients of power series A(x) consist entirely of squares, where A(x) = A083352(x)^2 + A083352(x) - 1.at n=43A083353
• SuperRefactorable numbers: m=A005179(n) such that k=m/n is an integer.at n=34A110821
• Triangle generated by e.g.f.: A(x,y) = exp(x + y*(x^2+x^3)), read by rows of length [n/2+1].at n=34A118588
• Refactorable numbers k such that the number of odd divisors r is odd, the number of even divisors s is even and both r and s are divisors of k.at n=17A120349
• Even refactorable numbers k such that the number r of odd divisors is odd, the number s of even divisors is even, both r and s are divisors of k and k is the first number for which the triple (r,s,t) occurs, where t is the number of divisors of k.at n=12A120359
• a(n) = (n!)^2/phi(n!), where phi is Euler's totient function.at n=8A123476
• Triangle of coefficients of (x+1)*(x+3)*(x+6)*...*(x+n(n+1)/2).at n=35A128813
• Square numbers with more divisors than any smaller square number.at n=14A136404
• Triangle T, read by rows, such that row n equals column 0 of matrix power M^n where M is a triangular matrix defined by M(k+m,k) = binomial(k+m,k) for m=0..2 and zeros elsewhere. Width-2-restricted finite functions.at n=45A141765
• Triangle of characteristic polynomials, see Mathematica code.at n=29A158390