18144

Appears in sequences

• a(n) is the concatenation of n and 8n.at n=17A009470
• Triangle T(n,k) read by rows, arising in enumeration of catafusenes.at n=51A024462
• Words over signatures (derived from multisets and multinomials).at n=49A035796
• For all n, if d is recursively applied to a(n) exactly 6 times then the fixed point of d-iteration is just reached.at n=26A036458
• Theta series of 14-dimensional lattice (SU(3,3) x C4).C2 with minimal norm 3.at n=7A047631
• Triangle of number of permutations of {1, 2, ..., n} having exactly k cycles, each of which is of length >=r for r=4.at n=7A050212
• 6-idempotent numbers.at n=3A050988
• Number of primitive (aperiodic) words of length n which contain exactly three different symbols.at n=8A056268
• a(n) = n! * (sum of reciprocals of all parts in unrestricted partitions of n).at n=5A057623
• Irregular triangle read by rows: T(n,k) = number of elements of order k in symmetric group S_n, for n >= 1, 1 <= k <= g(n), where g(n) = A000793(n) is Landau's function.at n=68A057731
• Decomposition of Stirling's S(n,2) based on associated numeric partitions.at n=20A058936
• Triangle of idempotent numbers binomial(n,k)*k^(n-k), version 1.at n=51A059297
• Triangle of idempotent numbers binomial(n,k)*k^(n-k), version 2.at n=41A059298
• Triangle of idempotent numbers (version 3), T(n, k) = binomial(n, k) * (n - k)^k.at n=48A059299
• Triangle of idempotent numbers binomial(n,k)*k^(n-k), version 4.at n=39A059300
• Numbers k such that k = phi(sigma(phi(sigma(phi(sigma(k)))))).at n=16A067884
• Numbers n such that n*sigma(n) is a perfect square.at n=13A069070
• Numbers k such that A069088(k) divides k.at n=39A069145
• a(n) = denominator(b(n)), where b(1) = b(2) = 1, b(n) = (b(n-1) + b(n-2))/(n-1).at n=9A069944
• Sum of numbers in n-th row of A070861.at n=7A070863