

A178311


Davis's upper bound for span(P^m x P^111) with m = 3 * (2^n  1) for 5 <= n <= 17, and P^k denoting real projective space.


0



32, 46, 50, 52, 78, 86, 94, 102, 106, 158, 166, 174, 182
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OFFSET

5,1


COMMENTS

From Table 3.2, p.10, of Davis. The span of a manifold is its maximum number of linearly independent vector fields. We discuss the question, still unresolved, of whether span(P^m x P^n) always equals span(P^m) + span(P^n). Here P^n denotes real projective space. We use BPcohomology to obtain new upper bounds for span(P^m x P^n), much stronger than previously known bounds.


LINKS

Table of n, a(n) for n=5..17.
Donald M. Davis, Vector fields on RP^m x RP^n, Dec 17, 2010.


CROSSREFS

Sequence in context: A304924 A306164 A317381 * A319914 A167527 A114406
Adjacent sequences: A178308 A178309 A178310 * A178312 A178313 A178314


KEYWORD

nonn


AUTHOR

Jonathan Vos Post, Dec 20 2010


STATUS

approved



