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Number of minimal edge cuts in the n-Plummer-Toft graph.
0

%I #9 Dec 11 2024 15:05:18

%S 12,22,38,65,113,202,372,703,1355,2648,5222,10357,20613,41110,82088,

%T 164027,327887,655588,1310970,2621713,5243177,10486082,20971868,

%U 41943415,83886483,167772592,335544782,671089133,1342177805,2684355118,5368709712,10737418867

%N Number of minimal edge cuts in the n-Plummer-Toft graph.

%C The sequence has been extended to n=0 using the formula. - _Andrew Howroyd_, Dec 11 2024

%H Andrew Howroyd, <a href="/A378924/b378924.txt">Table of n, a(n) for n = 0..500</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MinimalEdgeCut.html">Minimal Edge Cut</a>.

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Plummer-ToftGraph.html">Plummer-Toft Graph</a>.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (5,-9,7,-2).

%F From _Andrew Howroyd_, Dec 11 2024: (Start)

%F a(n) = 5*2^n + (n+2)*(n+7)/2.

%F G.f.: (12 - 38*x + 36*x^2 - 11*x^3)/((1 - x)^3*(1 - 2*x)). (End)

%o (PARI) a(n) = (n+2)*(n+7)/2 + 5*2^n \\ _Andrew Howroyd_, Dec 11 2024

%Y Cf. A377769.

%K nonn,easy,new

%O 0,1

%A _Eric W. Weisstein_, Dec 11 2024

%E a(0)=12 prepended and a(8) onwards from _Andrew Howroyd_, Dec 11 2024