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%I #11 Jul 16 2020 06:24:37
%S 0,3,140,5175,183000,6416875,224662500,7863609375,275228750000,
%T 9633019921875,337155773437500,11800452490234375,413015839453125000,
%U 14455554393310546875,505944403833007812500,17708054134515380859375,619781894709960937500000,21692366314858856201171875
%N 1/10 of the number of permutations of 4 indistinguishable copies of 1..n with exactly 2 local maxima.
%H Andrew Howroyd, <a href="/A152504/b152504.txt">Table of n, a(n) for n = 1..200</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (45,-375,875).
%F a(n) = (11*35^(n-1) - 11*5^(n-1) - 12*(n-1)*5^(n-1))/90. - _Andrew Howroyd_, May 10 2020
%F From _Colin Barker_, Jul 16 2020: (Start)
%F G.f.: x^2*(3 + 5*x) / ((1 - 5*x)^2*(1 - 35*x)).
%F a(n) = 45*a(n-1) - 375*a(n-2) + 875*a(n-3) for n>3.
%F (End)
%o (PARI) a(n) = {(11*35^(n-1) - 11*5^(n-1) - 12*(n-1)*5^(n-1))/90} \\ _Andrew Howroyd_, May 10 2020
%o (PARI) concat(0, Vec(x^2*(3 + 5*x) / ((1 - 5*x)^2*(1 - 35*x)) + O(x^20))) \\ _Colin Barker_, Jul 16 2020
%Y Cf. A152494, A334773.
%K nonn,easy
%O 1,2
%A _R. H. Hardin_, Dec 06 2008
%E Terms a(9) and beyond from _Andrew Howroyd_, May 10 2020
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