

A220131


Number of tilings of an n X 6 rectangle using integersided rectangular tiles of area n.


2



1, 1, 13, 6, 35, 3, 46, 1, 35, 6, 15, 1, 88, 1, 13, 8, 35, 1, 46, 1, 37, 6, 13, 1, 88, 3, 13, 6, 35, 1, 48, 1, 35, 6, 13, 3, 88, 1, 13, 6, 37, 1, 46, 1, 35, 8, 13, 1, 88, 1, 15, 6, 35, 1, 46, 3, 35, 6, 13, 1, 90, 1, 13, 6, 35, 3, 46, 1, 35, 6, 15, 1, 88, 1, 13
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OFFSET

0,3


COMMENTS

1 followed by period 60: (1, 13, ..., 90) repeated; offset 0.


LINKS



FORMULA

G.f.: see Maple program.


EXAMPLE

a(3) = 6, because there are 6 tilings of a 3 X 6 rectangle using integersided rectangular tiles of area 3:
._._._._._._. ._____._._._. ._._____._._.
       _____     _____  
       _____     _____  
______ ________ ________
._._._____._. ._._._._____. ._____._____.
  _____     _____ __________
  _____     _____ __________
________ ________ __________


MAPLE

gf:= (89*x^16 +90*x^15 +103*x^14 +109*x^13 +144*x^12 +58*x^11 +103*x^10 +91*x^9 +120*x^8 +91*x^7 +103*x^6 +58*x^5 +56*x^4 +21*x^3 +15*x^2 +2*x +1) / (x^16 +x^15 +x^14 +x^13 +x^12 x^4 x^3 x^2 x 1):
a:= n> coeff(series(gf, x, n+1), x, n):
seq(a(n), n=0..100);


CROSSREFS



KEYWORD

nonn,easy


AUTHOR



STATUS

approved



