

A007380


Number of 5thorder maximal independent sets in path graph.
(Formerly M0132)


21



1, 2, 1, 3, 1, 4, 2, 5, 4, 6, 7, 7, 11, 9, 16, 13, 22, 20, 29, 31, 38, 47, 51, 69, 71, 98, 102, 136, 149, 187, 218, 258, 316, 360, 452, 509, 639, 727, 897, 1043, 1257, 1495, 1766, 2134, 2493, 3031, 3536, 4288, 5031, 6054, 7165, 8547, 10196
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OFFSET

1,2


REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
R. Yanco and A. Bagchi, "Kth order maximal independent sets in path and cycle graphs", J. Graph Theory, submitted, 1994.


LINKS

Table of n, a(n) for n=1..53.
R. Yanco, Letter and Email to N. J. A. Sloane, 1994
R. Yanco and A. Bagchi, Kth order maximal independent sets in path and cycle graphs, Unpublished manuscript, 1994. (Annotated scanned copy)


FORMULA

Apparently, a(n) = a(n2) + a(n7) with g.f. x*(1+2*x+x^3+x^5+x^6)/(1+x^2+x^7).  R. J. Mathar, Oct 30 2009
a(n) = T(2, 7, n + 7) where T(a, b, n) = Sum_{a*x+b*y = n, x >= 0, y >= 0} binomial(x+y, y).  Sean A. Irvine, Jan 02 2018


CROSSREFS

Sequence in context: A246582 A059499 A113322 * A319162 A029171 A322994
Adjacent sequences: A007377 A007378 A007379 * A007381 A007382 A007383


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Mira Bernstein


EXTENSIONS

More terms from Sean A. Irvine, Jan 02 2018


STATUS

approved



