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A069325
Number of 3 X n binary arrays with path of adjacent 1's from upper right corner to lower left corner.
21
1, 8, 51, 295, 1632, 8830, 47239, 251261, 1332456, 7055228, 37327007, 197404203, 1043751584, 5518106750, 29171471659, 154210451661, 815197197636, 4309313949364, 22779900825195, 120418887728947
OFFSET
1,2
LINKS
FORMULA
G.f.: x*(1-x+x^3)/((1-2*x-2*x^2)*(2*x^5-4*x^4+x^3+9*x^2-7*x+1)). - Vladeta Jovovic, Jul 02 2003
MATHEMATICA
CoefficientList[Series[x*(1-x+x^3)/((1-2*x-2*x^2)*(2*x^5-4*x^4+x^3+9*x^2 -7*x+1)), {x, 0, 50}], x] (* G. C. Greubel, Apr 22 2018 *)
LinearRecurrence[{9, -21, 3, 24, -8, -4, 4}, {1, 8, 51, 295, 1632, 8830, 47239}, 20] (* Harvey P. Dale, May 21 2023 *)
PROG
(PARI) Vec(-x*(1-x+x^3)/(2*x^2+2*x-1)/(2*x^5-4*x^4+x^3+9*x^2-7*x+1) + O(x^99)) \\ Charles R Greathouse IV, Jun 12 2015
(Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(x*(1-x+x^3)/((1-2*x-2*x^2)*(2*x^5-4*x^4+x^3+9*x^2-7*x+1)))); // G. C. Greubel, Apr 22 2018
CROSSREFS
Row 3 of A359575.
Cf. 2 X n A048739, 4 X n A069326, 5 X n A069327, 6 X n A069328, 7 X n A069329, 8 X n A069330, 9 X n A069331, 10 X n A069332, 11 X n A069333, 12 X n A069334, 13 X n A069335, 14 X n A069336, 15 X n A069337, 16 X n A069338, 17 X n A069339, 18 X n A069340, 19 X n A069341, 20 X n A069342, n X n A069343, n X n symmetric A069344.
Sequence in context: A054620 A034516 A240360 * A295348 A082135 A153594
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, Mar 16 2002
STATUS
approved