OFFSET
1,2
REFERENCES
W. Fulton, Intersection Theory 2.ed., Springer-Verlag, 1998, page 192.
LINKS
David Eisenbud and Brady Haran, The Journey to 3264, Numberphile video (2023).
Wikipedia, Steiner's conic problem
Wikipedia, Enumerative Geometry
Index entries for linear recurrences with constant coefficients, signature (11,-55,165,-330,462,-462,330,-165,55,-11,1).
FORMULA
a(n) = n^5 * ((n-1)^5 + 10*(n-1)^4 + 40*(n-1)^3 + 40*(n-1)^2 + 10*(n-1) + 1).
EXAMPLE
a(2)=3264 because there are 3264 conics tangent to five conics in general position (Steiner's conic problem).
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Niccolò Castronuovo, Jun 07 2020
STATUS
approved