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A110971
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Triangle T(n,k) (n >= 2, 1 <= k <= n-1) read by rows: row n gives epispectrum of a path P_n (see reference for precise definition).
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2
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1, 1, 1, 1, 2, 1, 1, 2, 4, 1, 1, 2, 6, 6, 1, 1, 2, 7, 11, 10, 1, 1, 2, 8, 14, 24, 14, 1, 1, 2, 9, 16, 35, 42, 22, 1, 1, 2, 10, 18, 45, 68, 81, 30, 1, 1, 2, 11, 20, 55, 89, 149, 138, 46, 1, 1, 2, 12, 22, 66, 110, 216, 282, 250, 62, 1, 1, 2, 13, 24, 78, 132, 285, 422, 577, 419
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OFFSET
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2,5
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LINKS
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Table of n, a(n) for n=2..77.
Toufik Mansour, Armend Sh. Shabani, Bargraphs in bargraphs, Turkish Journal of Mathematics (2018) Vol. 42, Issue 5, 2763-2773.
M. A. Michels and U. Knauer, The congruence classes of paths and cycles, Discr. Math., 309 (2009), 5352-5359.
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EXAMPLE
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Triangle begins:
1;
1, 1;
1, 2, 1;
1, 2, 4, 1;
1, 2, 6, 6, 1;
1, 2, 7, 11, 10, 1;
1, 2, 8, 14, 24, 14, 1;
1, 2, 9, 16, 35, 42, 22, 1;
1, 2, 10, 18, 45, 68, 81, 30, 1;
1, 2, 11, 20, 55, 89, 149, 138, 46, 1;
1, 2, 12, 22, 66, 110, 216, 282, 250, 62, 1;
1, 2, 13, 24, 78, 132, 285, 422, 577, 419, 94, 1;
1, 2, 14, 26, 91, 156, 364, 568, 945, 1070, 732, 126, 1;
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CROSSREFS
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Cf. A152086, A102699.
Sequence in context: A137855 A113143 A181802 * A136788 A334622 A136450
Adjacent sequences: A110968 A110969 A110970 * A110972 A110973 A110974
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KEYWORD
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nonn,tabl
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AUTHOR
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N. J. A. Sloane, Sep 20 2009
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STATUS
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approved
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