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A008588
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Multiples of 6.
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28
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0, 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, 102, 108, 114, 120, 126, 132, 138, 144, 150, 156, 162, 168, 174, 180, 186, 192, 198, 204, 210, 216, 222, 228, 234, 240, 246, 252, 258, 264, 270, 276, 282, 288, 294, 300, 306, 312, 318, 324, 330, 336, 342, 348
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| For n>3, the number of squares on the infinite 3-column half-strip chessboard at <=n knight moves from any fixed point on the short edge.
Second differences of A000578. - Cecilia Rossiter (cecilia(AT)noticingnumbers.net), Dec 15 2004
A008615(a(n)) = n. - Reinhard Zumkeller, Feb 27 2008
A157176(a(n)) = A001018(n). [From Reinhard Zumkeller, Feb 24 2009]
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Tanya Khovanova, Recursive Sequences
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 318
Index to sequences with linear recurrences with constant coefficients, signature (2,-1).
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FORMULA
| a(n) = 6*n = 2*a(n-1)-a(n-2). G.f.: 6*x/(1-x)^2. [From Vincenzo Librandi, Dec 24 2010]
a(n)=Sum_k>=0 {A030308(n,k)*6*2^k}. - From DELEHAM Philippe, Oct 24 2011.
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MAPLE
| [ seq(6*n, n=0..45) ];
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MATHEMATICA
| Range[0, 500, 6] (* From Vladimir Joseph Stephan Orlovsky, May 26 2011 *)
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PROG
| (MAGMA) [6*n: n in [0..60] ]; // Vincenzo Librandi, Jul 16 2011
(PARI) a(n)=6*n \\ Charles R Greathouse IV, Feb 08 2012
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CROSSREFS
| Essentially the same as A008458.
Cf. A016921, A016933, A016945, A016957, A016969.
Sequence in context: A126798 A175130 A008458 * A078596 A187389 A085129
Adjacent sequences: A008585 A008586 A008587 * A008589 A008590 A008591
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KEYWORD
| nonn,easy,changed
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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