

A191783


Numbers k such that the topological ksphere has a unique differentiable structure up to diffeomorphism.


0




OFFSET

1,2


COMMENTS

Whether 4 is a term is an open question.  Andrey Zabolotskiy, Feb 02 2018
Except (possibly) for k=4, these are the numbers k such that A001676(k)=1.  Jeppe Stig Nielsen, May 22 2019


LINKS

Table of n, a(n) for n=1..7.
John W. Milnor, Differential Topology Fortysix Years Later, Notices Amer. Math. Soc. 58 (2011), 804809.


CROSSREFS

Cf. A001676.
Sequence in context: A007435 A125877 A118787 * A098930 A075372 A064725
Adjacent sequences: A191780 A191781 A191782 * A191784 A191785 A191786


KEYWORD

nonn,more,hard


AUTHOR

N. J. A. Sloane, Jun 25 2011


EXTENSIONS

Definition rewritten by Jeppe Stig Nielsen, May 22 2019


STATUS

approved



