30784

Appears in sequences

• Number of loopless rooted planar maps with 4 faces and n vertices and no isthmuses.at n=9A006417
• Number of sublattices of index n in generic 4-dimensional lattice.at n=30A038991
• Mean divisor of n differs by <= 1 from mean divisor of all numbers from 1 to n-1.at n=24A049010
• a(n) = n^3 + n^2 + n + 1.at n=31A053698
• a(n) = Z(S_m; sigma[1](n), sigma[2](n),..., sigma[m](n)) where Z(S_m; x_1,x_2,...,x_m) is the cycle index of the symmetric group S_m and sigma[k](n) is the sum of k-th powers of divisors of n; m=3.at n=30A068020
• a(n) = (4*(n+10)^n+n^n)/5.at n=4A083305
• a(n) = 1 + prime(n) + prime(n)^2 + prime(n)^3.at n=10A131991
• a(n) = Sum_{d|n} Moebius(n/d)*d^(b-1)/phi(n) for b = 5.at n=30A160891
• Sum of divisors of cubes.at n=30A175926
• Value of A114183 at end of n-th doubling run.at n=47A213656
• a(n) = (31^n - 1)/30.at n=4A218734
• Totient numbers (A002202) of the form 1 + k + k^2 + k^3 +...+ k^i (i > 1, k > 1).at n=16A282090
• Number of canonical 3-polytopes of size n.at n=18A319959
• Sum of the prime numbers appearing along the border of an n X n square array whose elements are the numbers from 1..n^2, listed in increasing order by rows.at n=45A344846
• Integers k such that k^2 can be written as the sum of three positive fourth powers.at n=9A365657
• G.f. satisfies A(x) = 1 + 2*x*A(x) + 2*x^4*A(x)^4.at n=10A367115
• The sum of divisors of the smallest cubefull number that is a multiple of n.at n=30A369720
• The sum of divisors of the smallest cubefull exponentially odd number that is divisible by n.at n=30A369758
• a(n) = sigma_1(n) * sigma_2(n).at n=30A379812
• a(n) is the smallest integer k > 2*n such that Product_{i=1..n} (k - i) has no prime factor p in n < p < 2*n.at n=32A386620