30420

Appears in sequences

• Pentagonal pyramidal numbers: a(n) = n^2*(n+1)/2.at n=39A002411
• Even pentagonal pyramidal numbers.at n=29A015224
• a(n) = (2*n - 7)*n^2.at n=26A015242
• a(n) = n + (n+1)^2 + (n+2)^3 + (n+3)^4.at n=10A027621
• Arithmetic derivative of cubes: a(n) = 3*n^2*A003415(n).at n=25A068721
• Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={-1,0,2}.at n=38A080001
• Group the natural numbers such that the n-th group sum is divisible by the n-th triangular number: (1), (2, 3, 4), (5, 6, 7), (8, 9, 10, 11, 12), (13, 14, 15, 16, 17), (18, 19, 20, 21, 22, 23, 24), ... Sequence contains the group sum.at n=38A086500
• Numbers n divisible by exactly two nontrivial permutations (rearrangements) of the digits of n.at n=28A090057
• Triangle read by rows: T(n,k) is number of Grand Motzkin paths of length n having k returns to the x-axis (i.e., d or u steps hitting the x-axis).at n=50A109193
• a(n) = n^3 + 114 * n.at n=29A122562
• Exponential abundant numbers: integers k for which A126164(k) > k, or equivalently for which A051377(k) > 2k.at n=30A129575
• Interlacing n^3/2 and n^2(n + 1)/2.at n=38A130656
• a(n) = (n+1)*(2n+1)^2.at n=19A139757
• Number of ways to place 4 nonattacking amazons (superqueens) on a 4 X n board.at n=19A174642
• y(n) is the corresponding value of a(n) in sequence A181643. For a given n it is the minimum value such that a(n)*[a(n)+n]*[a(n)+n+n]=y*y.at n=37A181646
• Numbers with prime factorization pq^2r^2s^2.at n=15A189344
• Maximum value of k^2 * (n-k).at n=59A190798
• a(n) = 20*n^2.at n=39A195322
• Numbers such that k is the altitude of a Heronian triangle with sides m-13, m, m+13.at n=17A293846
• Pentagonal pyramidal numbers divisible by 3.at n=26A299412