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Search: id:A000205
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| A000205 |
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Number of positive integers <= 2^n of form x^2 + 3 y^2.
(Formerly M2350 N0928)
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+0
1
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| 1, 1, 3, 4, 8, 14, 25, 45, 82, 151, 282, 531, 1003, 1907, 3645, 6993, 13456, 25978, 50248, 97446, 189291, 368338, 717804, 1400699, 2736534, 5352182, 10478044, 20531668, 40264582, 79022464, 155196838, 304997408, 599752463, 1180027022, 2322950591, 4575114295
(list; graph; listen)
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OFFSET
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0,3
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
P. Moree and H. J. J. te Riele, The hexagonal versus the square lattice, Math. Comp. 73 (2004), no. 245, 451-473.
D. Shanks and L. P. Schmid, Variations on a theorem of Landau. Part I, Math. Comp., 20 (1966), 551-569.
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LINKS
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P. Moree and H. J. J. te Riele, The hexagonal versus the square lattice
Index entries for sequences related to populations of quadratic forms
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CROSSREFS
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Cf. A000050.
Adjacent sequences: A000202 A000203 A000204 this_sequence A000206 A000207 A000208
Sequence in context: A051788 A023623 A023558 this_sequence A136425 A005907 A049866
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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