22138

Appears in sequences

• Number of acyclic ketone and aldehyde stereo-isomers with n carbon atoms.at n=12A005957
• Number of similarity classes of triangles which can be drawn using the lattice points in an n X n grid for vertices.at n=20A028492
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 12.at n=17A031600
• Difference between the n-th partial sum of the squares (A000330) and the n-th partial sum of the primes (A007504).at n=41A108753
• The EG1 triangle.at n=19A162005
• G.f. satisfies: A(x) = exp( Sum_{n>=1} (A(x)^n + A(-x)^n) * x^n/n ).at n=9A171190
• Partial sums of floor(3^n/4).at n=9A178222
• Integers n such that the digit set of n^2 is {0,1,4,9}.at n=30A317579
• E.g.f.: S(x,k) = Integral C(x,k)*D(x,k)^2 dx, such that C(x,k)^2 - S(x,k)^2 = 1, and D(x,k)^2 - k^2*S(x,k)^2 = 1, as a triangle of coefficients read by rows.at n=16A322230
• E.g.f.: S(x,k) = -i * sn( i * Integral C(x,k) dx, k) such that C(x,k) = cn( i * Integral C(x,k) dx, k), where S(x,k) = Sum_{n>=0} Sum_{j=0..n} T(n,j) * x^(2*n+1)*k^(2*j)/(2*n+1)!, as a triangle of coefficients T(n,j) read by rows.at n=19A325220