18920
domain: N
Appears in sequences
- Numbers k such that k-1, k-3, k-7 and k-9 are all prime.at n=17A064974
- Expansion of Product_{k>=1} (1 + A001055(k)*x^k).at n=42A066816
- a(n) = Sum_{d divides n} (-1)^(n/d+1)*d^3.at n=27A078307
- Fourth column (m=3) of (1,6)-Pascal triangle A096956.at n=42A096957
- Numbers k such that k and k+1 have 4 distinct prime factors.at n=23A140078
- Greatest number m such that the fractional part of (10/9)^A153695(m) >= 1-(1/m).at n=15A153699
- a(n) = 100*n^2 - 49*n + 6.at n=13A157651
- a(n) = 10*n*(n+1).at n=43A163761
- Number of noncrossing partitions up to rotation and reflection of an n-set without singleton blocks.at n=17A303931
- Numbers k such that k and k+1 each have at least 4 distinct prime factors.at n=23A321504
- First term of n-th difference sequence of (floor(k*r)), r = sqrt(7), k >= 0.at n=22A325672
- a(n) = Sum_{i+j<=m+1} t_i * t_j, where t_1 < ... < t_m are the totatives of n.at n=32A341063
- Geometric length of the solution to the Towers of Hanoi exchanging disks puzzle with 3 pegs and n disks.at n=13A341583
- Numbers k such that A360327(k) = A360327(k+1) > 1.at n=3A360358