340340
domain: N
Appears in sequences
- Number of nonsquare rectangles on an n X n board.at n=33A052149
- n*(n-1)*(n-2)*(n-3)*(n-4)*(2*n-1)/72.at n=17A055504
- Triangle read by rows: T(n,k) is the number of 2-stack sortable n-permutations with k runs.at n=59A082680
- Triangle read by rows: T(n,k) is the number of 2-stack sortable n-permutations with k runs.at n=61A082680
- Triangle read by rows: T(n,k) = (2 * (binomial(n,k)) * (n + 2 * k + 3)!)/((k + 1)! * (k + 2)! * (n + 3)!).at n=25A087727
- a(n) = 14*binomial(n,8).at n=17A088625
- Denominators of row sums in triangle described in A093412.at n=16A093419
- Denominator of -3*n + 2*(1+n)*HarmonicNumber(n).at n=17A096620
- Triangle read by rows: T(n,k) = binomial(3k,k)*binomial(n+k,3k)/(2k+1) (0 <= k <= floor(n/2)).at n=53A108759
- Triangle read by rows: T(n,k) is the number of ordered trees with n edges and 2k nodes of odd degree (not outdegree; 1 <= k <= ceiling(n/2)).at n=46A127157
- Denominators of 6*(sum(1/binomial(2*k,k),k=1..n)-1/3), n>=1.at n=8A130548
- a(n) = LCM of the integers b(k), over all k where 1 <= k <= n, where b(k) = the k-th integer from among those positive integers which are coprime to (n+1-k).at n=9A132421
- Denominators of the difference between the squarefree totient analogs of the harmonic numbers and the harmonic numbers: F_n - H_n.at n=17A138321
- Denominator of the Harary number for the cycle graph C_n.at n=35A160047
- Denominator of the Harary number for the path graph P_n.at n=17A160049
- Denominator of Integral_{x=0..1} Product_{k=1..n} (1-x^k) dx.at n=5A258230
- Triangle read by rows: T(n,k) = binomial(2*n+1, 2*k+1)*binomial(2*n-2*k, n-k)/(n+1-k) for 0 <= k <= n.at n=40A281000
- Triangle read by rows in which row(n) = {T(n, k)} is the lexicographically earliest list of n numbers such that adding 1 to some T(n, k) gives a row of numbers each divisible by prime(k).at n=22A286947
- Denominators of the partial sums of the reciprocals of the sum of unitary divisors function (A034448).at n=32A379514
- a(n) = Sum_{k=0..floor(3*n/8)} binomial(k+2,2) * binomial(k,3*n-8*k).at n=44A392316