1572480

Appears in sequences

• Number of aperiodic necklaces with n labeled beads of 3 colors.at n=6A032322
• Triangle T(n,k) = d(n-k,n), 0 <= k <= n, where d(l,m) = Sum_{k=l..m} 2^k * binomial(2*m-2*k, m-k) * binomial(m+k, m) * binomial(k, l).at n=24A067001
• Location of records in A099564.at n=23A099565
• a(1) = 1. For n >= 2, a(n) = sum of the two (not necessarily distinct) earlier terms, a(j) and a(k), which maximizes d(a(j)+a(k)), where d(m) is the number of positive divisors of m. a(n) = the minimum (a(j)+a(k)) if more than one such sum has the maximum number of divisors.at n=25A115387
• Number of "ups" and "downs" in the permutations of [n] if either a previous counted "up" ("down") or a "void" precedes an "up" ("down") which then will be counted also.at n=7A120928
• a(n) = sigma(lcm(1,2,...,n)) = A000203(A003418(n)).at n=12A124052
• a(n) = sigma(lcm(1,2,...,n)) = A000203(A003418(n)).at n=13A124052
• a(n) = sigma(lcm(1,2,...,n)) = A000203(A003418(n)).at n=14A124052
• Coefficients of a polynomial representation of the integral of 1/(x^4 + 2*a*x^2 + 1)^(n+1) from x = 0 to infinity.at n=24A126936
• Triangle T(n,k), 1 <= k <= n, read by rows: T(n,k) is the number of permutations in the symmetric group S_n having k multiplicative 3-excedances. Equivalently, the number of permutations of the set {3,6,9,...,3n} with k excedances.at n=52A136717
• Triangle T(n,k), 1 <= k <= n, read by rows: T(n,k) is the number of permutations in the symmetric group S_n having k multiplicative 3-excedances. Equivalently, the number of permutations of the set {3,6,9,...,3n} with k excedances.at n=53A136717
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k entries divisible by 3 that are followed by a smaller entry (n>=1, k>=0).at n=22A136718
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k entries divisible by 3 that are followed by a smaller entry (n>=1, k>=0).at n=23A136718
• a(n) = sum of divisors of A094348(n).at n=37A182941
• Number m that give records for the quotient between the maximum and minimum x's such that sigma(x)=m.at n=21A241854
• Highly composite numbers of class 3 (see comment in A275239).at n=33A275241
• Number of 4-cycles in the n-triangular honeycomb queen graph.at n=27A289705
• Largest FDH number of a strict integer partition of n.at n=38A299758
• T(n,k) = Sum_{j=1..n} 2^j*binomial(2*n-2*j, n-j)*binomial(n+j, n)*binomial(j, k), triangle read by rows (n >= 0 and 0 <= k <= n).at n=24A335183
• Binary Niven numbers (A049445) with a record gap to the next binary Niven number.at n=20A337077