A110971 - OEIS

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A110971

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).

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

2,5

LINKS

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.

EXAMPLE

Triangle begins:

1, 1;

1, 2, 1;

1, 2, 4, 1;