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A003878
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Number of stacks of n pikelets, distance 4 flips from a well-ordered stack.
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1
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1, 3, 48, 199, 543, 1191, 2278, 3963, 6429, 9883, 14556, 20703, 28603, 38559, 50898, 65971, 84153, 105843, 131464, 161463, 196311, 236503, 282558, 335019, 394453, 461451, 536628, 620623, 714099, 817743
(list; graph; refs; listen; history; internal format)
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OFFSET
| 3,2
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REFERENCES
| Marc Paulhus (paulhus(AT)wanadoo.nl), Pikelets, Discrete Math, to be submitted.
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FORMULA
| n^4+9/2*n^3+n^2-9/2*n+1.
G.f.:(-1-3*x^4+21*x^3-43*x^2+2*x)/(x-1)^5 [From Maksym Voznyy (voznyy(AT)mail.ru), Aug 10 2009]
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CROSSREFS
| Sequence in context: A088718 A016548 A162333 * A073982 A140650 A081540
Adjacent sequences: A003875 A003876 A003877 * A003879 A003880 A003881
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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