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A143094 Arises in counting relative Milnor rings in K-theory. 1
1, 2, 5, 15, 47, 145, 470 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
Column 3 of Marshall table, p. 443. A143093 is the analogous enumeration, column 2 of Marshall table, if we view the K-structures as graded rings with distinguished element.
REFERENCES
Ido Efrat, Valuations, orderings and Milnor K-theory, Mathematical Surveys and Monographs, vol. 124, American Mathematical Society, 2006.
Murray Marshall, Book Review: Valuations, orderings and Milnor K-theory, by Ido Efrat, Bulletin of the American Mathematical Society, Vol. 45 (July 2008) No. 3, pp. 439-444.
LINKS
FORMULA
a(n) = the number of nonisomorphic elementary types K_*(F)/S with |F^X/S| = 2^n, if we view the K-structures just as graded rings.
CROSSREFS
Cf. A143093.
Sequence in context: A148361 A346521 A148362 * A308274 A058495 A287275
KEYWORD
more,nonn
AUTHOR
Jonathan Vos Post, Jul 23 2008
STATUS
approved

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Last modified March 29 00:26 EDT 2024. Contains 371264 sequences. (Running on oeis4.)