login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A331445 Complete list of numbers of twisted cubics on a general Calabi-Yau threefold which is a complete intersection in some projective space. 1
317206375, 15655168, 6424326, 1611504, 416256 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

There are exactly five types of such threefolds: the quintic in P^4, the complete intersections (3, 3) and (2, 4) in P^5, the complete intersection (2, 2, 3) in P^6 and finally (2, 2, 2, 2) in P^7. The counts are listed in that order.

LINKS

Table of n, a(n) for n=1..5.

Geir Ellingsrud and Stein Arild Stromme, Bott's formula and enumerative geometry, J. Amer. Math. Soc. 9 (1996), 175-193; arXiv:alg-geom/9411005, 1994. See Th. 1.1.

CROSSREFS

Sequence in context: A219784 A105005 A157789 * A331446 A184573 A112429

Adjacent sequences:  A331442 A331443 A331444 * A331446 A331447 A331448

KEYWORD

nonn,fini,full

AUTHOR

N. J. A. Sloane, Jan 22 2020

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 23 08:14 EDT 2022. Contains 353961 sequences. (Running on oeis4.)