9434880

Appears in sequences

• Number of 2n-bead balanced binary strings of fundamental period 2n, rotationally equivalent to reverse, complement and reversed complement.at n=36A045665
• E.g.f. (1-x)/(1-x-2x^3).at n=9A052601
• Expansion of e.g.f. (1 - x - sqrt(1-2*x+x^2-4*x^3))/(2*x).at n=9A052723
• A simple context-free grammar in a labeled universe: a(n) = A052743(n)-A052723(n), n>1.at n=9A052724
• a(n) = Product_{k=1..n} sigma(k); sigma(k) is the sum of the positive divisors of n.at n=8A066780
• Ordered products of the perimeter and the sides of primitive Pythagorean triangles.at n=9A223857
• Coefficients in q-expansion of (E_2^2*E_4 - 2*E_2*E_6 + E_4^2)/1728, where E_2, E_4, E_6 are the Eisenstein series shown in A006352, A004009, A013973, respectively.at n=24A282099