A013640 f-vector for 20-dimensional simplicial polytope providing counterexample to unimodality conjecture.

1, 4203045807626, 84060916163336, 798578704207074, 4791472253296106, 20363758019368323, 65164051780016980, 162910744316489788, 325834059588060117, 529707205213463823, 709935971390166248, 805494832051588614, 821976324224631043, 821976324224611712, 822000129478641948, 747383755288236256, 546761228419958342, 293715859557026466, 106920718330384544, 23458617733909980, 2345861773390998

Offset

-1,2

Comments

Fails unimodality conjecture because a(11) > a(12) < a(13). - Sean A. Irvine, Aug 17 2018

References

G. M. Ziegler, Lect. on Polytopes, Springer 1995, p. 272.

Links

Table of n, a(n) for n=-1..19.

Crossrefs

Sequence in context: A186912 A288284 A233504 * A185431 A139574 A233625

Adjacent sequences: A013637 A013638 A013639 * A013641 A013642 A013643

Keyword

nonn,fini,full

Author

N. J. A. Sloane.

Extensions

More terms from Ziegler reference added by Sean A. Irvine, Aug 17 2018

Status

approved