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A003777
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Number of stacks of n pikelets, distance 3 flips from a well-ordered stack.
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3
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1, 11, 35, 79, 149, 251, 391, 575, 809, 1099, 1451, 1871, 2365, 2939, 3599, 4351, 5201, 6155, 7219, 8399, 9701, 11131, 12695, 14399, 16249, 18251, 20411, 22735, 25229, 27899, 30751, 33791, 37025, 40459
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| This sequence in related to A095794 by a(n)=n*A095794(n)-sum[A095794(i), i=1..n-1] for n>1. - Bruno Berselli, Dec 28 2010
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REFERENCES
| Marc Paulhus (paulhus(AT)wanadoo.nl), Pikelets, Discrete Math, to be submitted.
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LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (4,-6,4,-1).
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FORMULA
| a(n) = n^3+n^2-1.
G.f.: x*(1+7*x-3*x^2+x^3)/(1-x)^4. Also a(n) = 2*A002411(n)-1 = A000578(n-1)+A001107(n). - Bruno Berselli, Dec 28 2010
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MATHEMATICA
| Table[n^3+n^2-1, {n, 1, 100}] (*From Vladimir Joseph Stephan Orlovsky, Mar 09 2011*)
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PROG
| (MAGMA) [(n^3+n^2-1): n in [1..50]]; // Vincenzo Librandi, Apr 06 2011
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CROSSREFS
| Sequence in context: A118554 A092069 A103115 * A199817 A098116 A123749
Adjacent sequences: A003774 A003775 A003776 * A003778 A003779 A003780
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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