327600

Appears in sequences

• Expansion of e.g.f. (2 - 4*x + x^2)/((1 - x)*(1 - 2*x)).at n=7A052584
• a(n) = 3*(n-2)*(n-3)*(3*n^2-3*n-8)/2.at n=16A064198
• Numbers n such that n*sigma(n) is a perfect square.at n=30A069070
• a(0) = 1, a(n) = 20*sigma[3](n).at n=24A091983
• Numbers that can be expressed as the difference of the squares of primes in exactly ten distinct ways.at n=22A092006
• Number of non-palindromic divisors of n sets a new record.at n=38A093037
• If X_1,...,X_n is a partition of a 2n-set X into 2-blocks then a(n) is equal to the number of 4-subsets of X containing none of X_i, (i=1,...,n).at n=24A130810
• Numbers m that raised to the powers from 1 to k (with k>=1) are multiple of the sum of their digits (m raised to k+1 must not be a multiple). Case k=15.at n=11A135200
• a(n) = A143176(n)/n.at n=43A143177
• Triangle T(n,k) = binomial(2*n-k, k)*(n-k)!, read by rows.at n=48A155856
• Triangle T(n, k) = binomial(n+k, 2*k)*k!, read by rows.at n=51A156367
• Number of reduced words of length n in Coxeter group on 5 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I.at n=9A164706
• Areas for which there are more tatami-free rooms (cf. A165633) than for any smaller size.at n=17A165762
• Ordered forests of k increasing plane unary-binary trees with n nodes.at n=32A185423
• G.f.: q-cosh(x,q)^2 - q-sinh(x,q)^2 at q=-x.at n=27A198200
• a(n) is the least number k for which A000005(k)/A222084(k) = n.at n=8A222086
• Largely composite numbers that are not highly composite.at n=52A244353
• Numbers k such that floor(Sum_{d|k} 1 / sigma(d)) = 3.at n=4A265713
• Ramanujan's largely composite numbers n (A067128) which are not divisible by all the primes < p, where p is the greatest prime divisor of n.at n=20A273379
• Highly composite numbers of class 1 (see comment).at n=32A275239