24129

Appears in sequences

• 4-dimensional analog of centered polygonal numbers. Also number of regions created by sides and diagonals of a convex n-gon in general position.at n=29A006522
• Number of regions in regular n-gon with all diagonals drawn.at n=28A007678
• Numbers k where cos(k) decreases monotonically to 0.at n=37A046957
• Numbers k where sin(k) increases monotonically to 1 (or cosec(k) decreases).at n=41A046959
• Starting numbers for which the RATS sequence has eventual period 3.at n=5A114613
• Coefficient of x in the reduction by x^2 -> x+1 of the polynomial p(n,x) defined at Comments.at n=16A192978
• Number of isomorphism classes of nanocones with 3 pentagons and a nearsymmetric boundary of length n.at n=40A198014
• a(n) = pg(n, 3) + pg(n, 4) + ... + pg(n, n) where pg(n, m) is the m-th n-th-order polygonal number.at n=20A245679
• G.f. A(x,y) satisfies: A(x,y) + A(1/x,y) = Sum_{m>=0} (x^m + y + 1/x^m)^m, ignoring the infinite constant term; this is the triangle, read by rows, of coefficients T(n,k) of x^n*y^k in A(x,y) for n >= 1, k = 0..n-1.at n=92A316590
• Number of regions in a polygon whose boundary consists of n+2 equally spaced points around the arc of a semicircle. See Comments for precise definition.at n=26A333643
• a(n) = A007678(2*n+1).at n=14A341735