A261187 a(n) = (2^(n-1))!*y(n) where y(n)=1/2*(y(n-1))^2+1 for n>=2 and y(1)=1.

1, 3, 51, 131355, 131953155208875, 5496027066067360087228913484456796875, 27805296606704951937976342299927372748633425216234990144120838935506416477839670037841796875

Offset: 1

Author

Alexander Karpov, Aug 11 2015

Keywords

• nonn

Comments

a(n) is also the number of knockout tournament seedings that satisfy the symmetry property.

Links

• Alexander Karpov, A theory of knockout tournament seedings, Heidelberg University, AWI Discussion Paper Series, No. 600.

Crossrefs

Cf. A067667 (number of seedings).

Programs

Mathematica

Table[(2^(n-1))!*FoldList[(1/2)*(#1)^2+1&,1,Range[2,7]][[n]],{n,1,7}] (* Ivan N. Ianakiev, Aug 25 2015 *)