OFFSET
0,3
COMMENTS
For tiling algorithm, see A351322.
LINKS
Index entries for linear recurrences with constant coefficients, signature (5,28,-69,-142,194,78,-57,-36,70,-32).
FORMULA
G.f.: (1 - 4*x - 16*x^2 + 37*x^3 + 32*x^4 - 34*x^5 + 4*x^6 + 2*x^7 - 2*x^8) / (1 - 5*x - 28*x^2 + 69*x^3 + 142*x^4 - 194*x^5 - 78*x^6 + 57*x^7 + 36*x^8 - 70*x^9 + 32*x^10).
a(n)=5*a(n-1) + 28*a(n-2) - 69*a(n-3) - 142*a(n-4) + 194*a(n-5) + 78*a(n-6) - 57*a(n-7) - 36*a(n-8) + 70*a(n-9) - 32*a(n-10).
EXAMPLE
a(2)=17, mirroring included (h: horizontal, v: vertical):
v v h,v v h
___ ___ ___ ___ ___ ___ ___ ___ ___ ___
| | | | | | |___| |___| | | | |___| |___| |___| | _|
|___| |___| |___| |_ | |___| |_|_| | | | |___| | | |_| |
|___| | | | | | | |_| |___| | | | |_|_| | | | |___| | |_|
|___| |_|_| |___| |___| |___| |_|_| |___| |_|_| |___| |___|
2 + 2 + 1 + 4 + 1 + 1 + 1 + 2 + 1 + 2 = 17.
PROG
(Maxima) See A352589.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gerhard Kirchner, May 14 2022
STATUS
approved