90865

Appears in sequences

• Array (a frieze pattern) defined by a(n,k) = (a(n-1,k)*a(n-1,k+1) - 1) / a(n-2,k+1), read by antidiagonals.at n=54A007754
• Strong pseudoprimes to base 86.at n=22A020312
• Numerators of continued fraction for left factorial.at n=23A056889
• a(0) = 0, a(1) = 1, a(2*n) = n*a(2*n-1) + a(2*n-2), a(2*n+1) = a(2*n) + a(2*n-1).at n=15A056921
• a(n) = n*a(n-1) - a(n-2), with a(-1) = 0, a(0) = 1.at n=10A058797
• Expansion of 1/(1 - 5*x - 4*x^3).at n=7A060928
• a(n) = (n-1)*a(n-1)-a(n-2), a(0)=0, a(1)=1.at n=10A121965
• Beach-Williams Pell numbers of type pqr (p,q,r primes).at n=9A212079
• Number of n X 1 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of elements above it, modulo 4.at n=13A239812
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where A(n,k) is Sum_{j=0..floor(n/2)} ((n-j)!/j!)*binomial(n-j,j)*k^(n-2*j)*(-1)^j.at n=64A305466
• Number of set partitions of strict multiset partitions of integer partitions of n.at n=15A330452