1491840

Appears in sequences

• Generalized tangent numbers.at n=6A002302
• Triangle of coefficients in expansion of D^n (tan x) in powers of tan x.at n=32A008293
• Expansion of e.g.f. 1/(1-x-2*x^3).at n=8A052610
• Expansion of e.g.f. (1-x)/(1-2*x+x^2-x^3).at n=8A052691
• Triangle read by rows: nonzero coefficients of the polynomials F_n(x) which express derivatives of tan(z) in terms of powers of tan(z).at n=31A101343
• Triangle T(n,k), 0 <= k <= n, read by rows, defined by T(0,0) = 1; T(0,k) = 0 if k < 0 or if k > 0; T(n,k) = k*T(n-1,k-1) + (k+2)*T(n-1,k+1).at n=50A107729
• Triangle read by rows: T(n,k) is the number of deco polyominoes of height n and having k 2-cell columns starting at level 0 (n >= 1; 0 <= k <= n-1).at n=45A121634
• Number of deco polyominoes of height n, having no 2-cell columns starting at level 0. A deco polyomino is a directed column-convex polyomino in which the height, measured along the diagonal, is attained only in the last column.at n=9A121635
• Triangle read by rows: coefficients in polynomials P_n(u) arising from the expansion of D^(n-1) (tan x) in increasing powers of tan x for n>=1 and 1 for n=0.at n=61A155100
• Number T(n,k) of partitions of n into parts of exactly k sorts; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=53A255970
• Number of graceful labelings for the complete tripartite graph K_{1,1,n}.at n=6A334307
• Triangle T(n,k) (n>=0, 0<=k<=n) read by rows: T(0,0)=T(1,1)=1; T(n,0) is the Euler number A000111(n-1) for n>=1; T(n,n-1) = T(n,n) = (n-2)! for n>=2; interior entries are given by T(n,k) = m*T(n-1,k-1)+(k+1)*T(n-1,k+1) where m = k if n+k is even or k-1 if n+k is odd.at n=61A350970
• a(n) = (n-1)! * Sum_{d|n} d^(n/d).at n=8A354851