65065

Appears in sequences

• a(n) = a(n-1) + a(n-2) + 1, with a(0) = 0 and a(1) = 8.at n=20A022313
• a(n) = 5*(n+1)*binomial(n+2, 5)/2.at n=9A027778
• a(n) = 5*(n+1)*binomial(n+2,10).at n=4A027783
• Number of nonempty subsets of {1,2,...,n} in which exactly 1/6 of the elements are <= (n-4)/2.at n=23A048069
• Nonpalindromic numbers m such that the difference between the square of m and the square of the reversal of m is itself a perfect square. Numbers ending in 0 are excluded.at n=4A202386
• Irregular triangle M_2(n,k) read by rows: number of maximum k-matchings in rooted plane trees of size n, 1<=k<=n/2, 2<=n.at n=43A219731
• Triangle read by rows: number of 321-avoiding ordered set partitions of [n] into k blocks, n>=1, 1<=k<=n.at n=42A227159
• Expansion of x^4/[(1+x)*Product_{k=1..3} (1-k*x)].at n=9A243869
• Self-inverse permutation of nonnegative integers, A075158-conjugate of the inverse of gray code: a(n) = 1 + A075157(A006068(A075158(n-1))).at n=45A245452
• Nonpalindromic positive integers k such that the absolute value of k^2 - reverse(k)^2 is a square.at n=13A256515
• Occurrences of decrease of the probability density P(n) of coprime numbers k,m, satisfying 1 <= k <= a(n) and 1 <= m <= a(n), and a(n) congruent to 1 (mod 2) and a(n) not congruent to 3 (mod 6).at n=26A280879
• Consider the e.g.f. A(x,y) = Sum_{n>=0} Sum_{k=0..n} T(n,k) * x^(2*n-2*k+1) * y^(2*k) / (2*n+1)! and related functions B(x,y) and C(x,y), as defined in the Formula section. Sequence gives the triangular array of coefficients T(n,k) (n>=0, 0<=k<=n) of A(x,y).at n=34A326797