18816
domain: N
Appears in sequences
- Numbers n such that n / product of digits of n is a square.at n=19A001104
- Coefficients of Laguerre polynomials.at n=3A001812
- Product of digits of 2^n.at n=27A014257
- Expansion of ( Sum_{k>=0} k*q^(k^2) )^8.at n=34A037217
- Triangle whose (i,j)-th entry is binomial(i,j)*7^(i-j)*8^j.at n=12A038274
- Triangle whose (i,j)-th entry is binomial(i,j)*8^(i-j)*7^j.at n=12A038285
- a(n) = T(2n,n), where T is given by A048113.at n=9A048116
- Triangle of coefficients of certain exponential convolution polynomials.at n=33A048786
- Triangle T(s,t), s >= 1, 1 <= t <= s (see formula line).at n=41A059836
- Sequence S_6 of the S_r family.at n=8A092184
- If p(k) is the k-th prime, then the n-th set of 3 consecutive cousin prime pairs starts at p(a(n)).at n=26A095970
- Forwards row convergent of triangle A096811, in which A096811(n,k) equals the k-th term of the convolution of the two prior rows indexed by (n-k) and (k-2).at n=15A096812
- a(n) = A062402(2^n+1).at n=13A096856
- Number of points of self-intersection of the path of a billiard ball traveling at a 45-degree angle on a prime(n) X prime(n+1) billiard table. Also equal to 1/2 the number of the lattice points lying within a prime(n) X prime(n+1) rectangle.at n=43A099407
- Numbers n such that (n + prime(n)), (n+1 + prime(n+1)), (n+2 + prime(n+2)) and (n+3 + prime(n+3)) are divisible by 5.at n=12A107582
- McKay-Thompson series of class 8D for the Monster group.at n=35A112143
- McKay-Thompson series of class 16b for the Monster group.at n=35A112151
- Triangle read by rows: T(n,k) is the number of Schroeder paths of length 2n and having k weak ascents (1<=k<=n). A Schroeder path of length 2n is a lattice path from (0,0) to (2n,0) consisting of U=(1,1), D=(1,-1) and H=(2,0) steps and never going below the x-axis. A weak ascent in a Schroeder path is a maximal sequence of consecutive U and H steps.at n=41A114655
- a(n,m) =Floor[N[(-2 + Sqrt[3])^n + (-2 - Sqrt[3])^n]/2^m].at n=28A117809
- Triangle read by rows: T(n,m) = 2*n^2*A084221(n) (n>=0, 0 <= m <= n).at n=35A122758