

A007386


Number of strict 7thorder maximal independent sets in path graph.
(Formerly M2199)


0



0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 3, 0, 6, 0, 10, 0, 15, 1, 21, 4, 28, 10, 36, 20, 45, 35, 56, 56, 71, 84, 93, 120, 126, 165, 175, 221, 246, 292, 346, 385, 483, 511, 666, 686, 906, 932, 1218, 1278, 1624, 1761, 2157, 2427, 2866, 3333, 3822, 4551
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OFFSET

1,11


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A. Bagchi, "Kth order maximal independent sets in path and cycle graphs", J. Graph Theory, submitted, 1994, apparently unpublished.


LINKS

Table of n, a(n) for n=1..56.
R. Yanco, Letter and Email to N. J. A. Sloane, 1994


FORMULA

Apparently, g.f. = x^9/((x^9+x^21)*(x1)^2*(1+x)^2) with recurrence a(n)= 3*a(n2)  3*a(n4) + a(n6) + a(n9)  2*a(n11) + a(n13).  R. J. Mathar, Oct 30 2009
a(n) = A007381(n)  b(n) where b(2*n+1) = 1 and b(2*n) = n+1.  Sean A. Irvine, Jan 02 2018


CROSSREFS

Cf. A007381.
Sequence in context: A161829 A290705 A115456 * A007385 A307644 A081978
Adjacent sequences: A007383 A007384 A007385 * A007387 A007388 A007389


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Mira Bernstein


EXTENSIONS

More terms from Sean A. Irvine, Jan 02 2018


STATUS

approved



