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Search: id:A084239
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| A084239 |
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Rank of K-groups of Furstenberg transformation group C*-algebras of n-torus. |
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+0
3
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| 1, 2, 3, 4, 6, 8, 13, 20, 32, 52, 90, 152, 268, 472, 845, 1520, 2766, 5044, 9277, 17112, 31724, 59008, 110162, 206260, 387282, 729096, 1375654, 2601640, 4929378, 9358944, 17797100, 33904324, 64678112, 123580884, 236413054, 452902072
(list; graph; listen)
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OFFSET
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0,2
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REFERENCES
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K. Reihani, C*-algebras from Anzai flows and their K-groups, preprint, 2003.
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FORMULA
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a(n) = constant term of prod(i=1, n, 1+t^(i-.5(n+1))) for odd n and a(n) = constant term of (1+t^(.5))*prod(i=1, n, 1+t^(i-.5(n+1))) for even n.
Sums of antidiagonals of A067059, i.e. a(n) is sum over k of number of partitions of [k(n-k)/2] into up to k parts each no more than n-k. Close to 2^(n+1)*sqrt(6/(pi*n^3)) and seems to be even closer to something like 2^(n+1)*sqrt(6/(pi*(n^3+0.9*n^2-0.1825*n+1.5))). - Henry Bottomley (se16(AT)btinternet.com), Jul 20 2003
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CROSSREFS
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Cf. A000980.
Sequence in context: A000029 A155051 A018137 this_sequence A049708 A000031 A111023
Adjacent sequences: A084236 A084237 A084238 this_sequence A084240 A084241 A084242
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KEYWORD
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nonn
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AUTHOR
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Kamran Reihani (reyhan_k(AT)modares.ac.ir), Jun 21 2003
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EXTENSIONS
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More terms from Henry Bottomley (se16(AT)btinternet.com), Jul 20 2003
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