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 A291375 Irregular triangle read by rows: number of  maximal irredundant sets of size k in the n-path graph. 2
 0, 1, 0, 2, 0, 1, 1, 0, 0, 4, 0, 0, 5, 1, 0, 0, 2, 6, 0, 0, 0, 12, 1, 0, 0, 0, 8, 9, 0, 0, 0, 1, 25, 1, 0, 0, 0, 0, 28, 12, 0, 0, 0, 0, 12, 44, 1, 0, 0, 0, 0, 2, 68, 16, 0, 0, 0, 0, 0, 48, 73, 1, 0, 0, 0, 0, 0, 14, 150, 20, 0, 0, 0, 0, 0, 1, 155, 112, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS For each row, k lies in the range 0..ceiling(n/2). The upper end of the range is the upper irredundance number of the graph. LINKS Andrew Howroyd, Table of n, a(n) for n = 1..990 Eric Weisstein's World of Mathematics, Maximal Irredundant Set Eric Weisstein's World of Mathematics, Path Graph FORMULA T(n,k) = 0 for k < ceiling(n/3). EXAMPLE Triangle begins: 0, 1; 0, 2; 0, 1, 1; 0, 0, 4; 0, 0, 5,  1; 0, 0, 2,  6; 0, 0, 0, 12,  1; 0, 0, 0,  8,  9; 0, 0, 0,  1, 25,  1; 0, 0, 0,  0, 28, 12; 0, 0, 0,  0, 12, 44,  1; 0, 0, 0,  0,  2, 68, 16; ... As polynomials these are: x; 2*x; x + x^2; 4*x^2; 5*x^2 + x^3; etc. CROSSREFS Row sums of A291055. Sequence in context: A219023 A025427 A245963 * A033778 A091586 A116377 Adjacent sequences:  A291372 A291373 A291374 * A291376 A291377 A291378 KEYWORD nonn,tabf AUTHOR Andrew Howroyd, Aug 23 2017 STATUS approved

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Last modified June 26 04:11 EDT 2019. Contains 324369 sequences. (Running on oeis4.)