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6th diagonal of triangle in A059317.
1

%I #15 Jan 05 2025 19:51:38

%S 0,0,0,0,3,22,82,218,476,914,1603,2628,4089,6102,8800,12334,16874,

%T 22610,29753,38536,49215,62070,77406,95554,116872,141746,170591,

%U 203852,242005,285558,335052,391062,454198,525106,604469,693008,791483,900694,1021482

%N 6th diagonal of triangle in A059317.

%H W. F. Klostermeyer, M. E. Mays, L. Soltes and G. Trapp, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/35-4/klostermeyer.pdf">A Pascal rhombus</a>, Fibonacci Quarterly, 35 (1997), 318-328.

%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-15,20,-15,6,-1).

%F For n>2, a(n) = (1/120) (n-3)(n^4+28n^3-71n^2-478n+1360).

%F From _Chai Wah Wu_, Mar 11 2021: (Start)

%F a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n > 8.

%F G.f.: x^4*(-3*x^2 + x + 3)*(-x^2 + x + 1)/(x - 1)^6. (End)

%o (PARI) a(n)=if(n>3,(n-3)*(n^4+28*n^3-71*n^2-478*n+1360)/120,0) \\ _Charles R Greathouse IV_, Oct 21 2022

%K nonn,easy

%O 0,5

%A _N. J. A. Sloane_, May 28 2005