OFFSET
0,7
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
Wikipedia, Hexomino
FORMULA
G.f.: See Maple program.
MAPLE
gf:= -(x^15-x^12-2*x^10-2*x^9+x^7+2*x^6+x^5+x^4+x^3-1) *(x-1)^5 *(x+1)^5 *(x^2+x+1)^5 *(x^2-x+1)^5 / (x^51 -x^48 -3*x^46 -8*x^45 +2*x^43 +8*x^42 +3*x^41 +18*x^40 +28*x^39 -x^38 -11*x^37 -29*x^36 -15*x^35 -45*x^34
-56*x^33 +5*x^32 +24*x^31 +61*x^30 +30*x^29 +60*x^28 +70*x^27 -10*x^26 -25*x^25 -80*x^24 -30*x^23 -45*x^22 -61*x^21 +10*x^20 +10*x^19 +71*x^18 +15*x^17 +28*x^16 +38*x^15 -5*x^14 -2*x^13 -43*x^12 -8*x^11 -8*x^10 -13*x^9 +x^8 -4*x^7 +14*x^6 +x^3 +x -1):
a:= n-> coeff(series(gf, x, n+1), x, n):
seq(a(n), n=0..40);
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Nov 26 2014
STATUS
approved