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Search: id:A086192
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| A086192 |
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Tribonacci numbers that start with first three squares. |
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+0
3
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| 1, 4, 9, 14, 27, 50, 91, 168, 309, 568, 1045, 1922, 3535, 6502, 11959, 21996, 40457, 74412, 136865, 251734, 463011, 851610, 1566355, 2880976, 5298941, 9746272, 17926189, 32971402, 60643863, 111541454, 205156719, 377342036, 694040209
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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n and a(n) are of the same parity. Except for the first three terms and a(5)=27, there is no perfect powers (A001597) in the first 225 terms. In fact there is always at least one factor which is represented only once. -Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 27 2003
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FORMULA
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a(n) = a(n-1) + a(n-2) + a(n-3).
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MATHEMATICA
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a[1] = 1; a[2] = 4; a[3] = 9; a[n_] := a[n] = a[n - 3] + a[n - 2] + a[n - 1]; Table[ a[n], {n, 1, 30}]
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CROSSREFS
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Cf. A000213.
Sequence in context: A099980 A004630 A073497 this_sequence A105503 A095169 A105703
Adjacent sequences: A086189 A086190 A086191 this_sequence A086193 A086194 A086195
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KEYWORD
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nonn,easy
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AUTHOR
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Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Aug 26 2003
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 27 2003
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