33480

Appears in sequences

• Rook polynomials.at n=7A005778
• Theta series of 10-dimensional 2-modular lattice of minimal norm 2.at n=11A029545
• Decimal part of a(n)^(1/3) starts with reversal of its integer part: first term of runs.at n=30A034309
• Number of squarefree quaternary words of length n.at n=10A051041
• Numbers k not in A065036 but such that tau(k) = omega(k)^3.at n=35A074853
• a(n) is the number of even permutations (of an n-set) with exactly 2 fixed points.at n=7A145220
• Triangle read by rows: T(n,k) is the number of even permutations (of an n-set) with exactly k fixed points.at n=47A145224
• Regular coverings having dihedral voltage groups: see Kwak-Lee reference in A160870 for precise definition.at n=4A160878
• a(n) = ((2^b-1)/phi(n))*Sum_{d|n} Moebius(n/d)*d^(b-1) for b = 5.at n=8A160894
• Numbers k such that phi(phi(k)) = sigma(rad(k)).at n=37A173748
• Numbers k such that sopfr(k + bigomega(k)) = sopfr(k).at n=33A187877
• Numbers with prime factorization p*q*r^3*s^3 (where p, q, r, s are distinct primes).at n=14A190108
• Least number k such that n*k^n +/- 1 are twin primes, or a(n) = 0 if no such number exists.at n=24A239735
• Integers n such that n^2 = 2*x*(y-x), where x and y are consecutive terms in A014574.at n=16A255230
• Triangle read by rows: coefficients of rook polynomials.at n=52A259985
• Triangular array with n-th row giving coefficients of polynomial Product_{k = 2..n} (k + n*t) for n >= 1.at n=18A260687
• Number of twins of prime quadruples < 10^n.at n=13A338866
• Number of integer partitions of 2n whose distinct parts sum to n.at n=31A364910
• Triangle read by rows: T(n,k) is the number of permutations in symmetric group S_n with (n-k) fixed points and an odd number of non-fixed point cycles. Equivalent to the number of cycles of n items with cycle type defined by non-unity partitions of k <= n that contain an odd number of parts.at n=52A373418
• E.g.f. A(x) satisfies A(x) = 1 + x*exp(x^3)*A(x)^3.at n=5A390611