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A034852
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Rows of (Pascal's triangle - Losanitsch's triangle) (n >= 0, k >= 0).
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2
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0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 2, 2, 2, 0, 0, 2, 4, 4, 2, 0, 0, 3, 6, 10, 6, 3, 0, 0, 3, 9, 16, 16, 9, 3, 0, 0, 4, 12, 28, 32, 28, 12, 4, 0, 0, 4, 16, 40, 60, 60, 40, 16, 4, 0, 0, 5, 20, 60, 100, 126, 100, 60, 20, 5, 0, 0, 5, 25, 80, 160, 226, 226, 160, 80, 25, 5, 0, 0, 6, 30, 110, 240
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 0,12
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COMMENTS
| Also number of linear unbranched n-4-catafusenes of C_{2v} symmetry.
Number of n-bead black-white reversible strings with k black beads; also binary grids; string is not palindromic. - Yosu Yurramendi (yosu.yurramendi(AT)ehu.es), Aug 08 2008
The first seven columns are A004526, A002620, A006584, A032091, A032092, A032093, A032094. Row sums give essentially A032085. - Yosu Yurramendi (yosu.yurramendi(AT)ehu.es), Aug 08 2008
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REFERENCES
| S. J. Cyvin et al., Unbranched catacondensed polygonal systems containing hexagons and tetragons, Croatica Chem. Acta, 69 (1996), 757-774.
S. M. Losanitsch, Die Isomerie-Arten bei den Homologen der Paraffin-Reihe, Chem. Ber. 30 (1897), 1917-1926.
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LINKS
| N. J. A. Sloane, Classic Sequences
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FORMULA
| Equals (A007318-A051159)/2. - Yosu Yurramendi (yosu.yurramendi(AT)ehu.es), Aug 08 2008
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EXAMPLE
| 0; 0 0; 0 1 0; 0 1 1 0; 0 2 2 2 0; 0 2 4 4 2 0; ...
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MATHEMATICA
| nmax = 12; t[n_?EvenQ, k_?EvenQ] := (Binomial[n, k] - Binomial[n/2, k/2])/ 2; t[n_?EvenQ, k_?OddQ] := Binomial[n, k]/2; t[n_?OddQ, k_?EvenQ] := (Binomial[n, k] - Binomial[(n-1)/2, k/2])/2; t[n_?OddQ, k_?OddQ] := (Binomial[n, k] - Binomial[(n-1)/2, (k-1)/2])/2; Flatten[ Table[t[n, k], {n, 0, nmax}, {k, 0, n}]] (* From Jean-François Alcover, Nov 15 2011, after Yosu Yurramendi *)
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CROSSREFS
| Cf. A007318, A034851, A051159.
Essentially the same as A034877.
Sequence in context: A037864 A181674 A181676 * A112790 A179835 A110857
Adjacent sequences: A034849 A034850 A034851 * A034853 A034854 A034855
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KEYWORD
| nonn,tabl,easy,nice
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu), May 04 2000
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