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A038740
T(n,n-3), array T as in A038738.
0
1, 9, 47, 188, 643, 1993, 5798, 16193, 44068, 118013, 312974, 825277, 2169045, 5690426, 14913861, 39066661, 102306471, 267879086, 701364436, 1836256726, 4807458872, 12586185670, 32951178868, 86267449214, 225851287529
OFFSET
3,2
FORMULA
G.f.: x^3/[(1-3x+x^2)(1-x)^6].
a(3)=1, a(4)=9, a(5)=47, a(6)=188, a(7)=643, a(8)=1993, a(9)=5798, a(10)=16193, a(n)=9*a(n-1)-34*a(n-2)+71*a(n-3)-90*a(n-4)+ 71*a(n-5)- 34*a(n-6)+9*a(n-7)-a (n-8) [From Harvey P. Dale, Jan 06 2012]
MATHEMATICA
Drop[CoefficientList[Series[x^3/((1-3x+x^2)(1-x)^6), {x, 0, 30}], x], 3] (* or *) LinearRecurrence[ {9, -34, 71, -90, 71, -34, 9, -1}, {1, 9, 47, 188, 643, 1993, 5798, 16193}, 30] (* Harvey P. Dale, Jan 06 2012 *)
CROSSREFS
Sequence in context: A274270 A100790 A055250 * A225428 A163614 A207318
KEYWORD
nonn
AUTHOR
Clark Kimberling, May 02 2000
STATUS
approved