OFFSET
1,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,1).
FORMULA
a(n)=a(n-5) for n >= 18. - Robert Israel, Oct 02 2020
G.f.: x*(4*x^16 + 4*x^15 + 2*x^14 + 2*x^13 + 3*x^12 - 2*x^11 + x^10 + x^9 - 2*x^8 + 8*x^7 + 8*x^6 - 8*x^5 - 9*x^4 - 4*x^3 - 13*x^2 - 12*x - 1)/(x^5 - 1). - Chai Wah Wu, May 07 2024
MAPLE
A[1]:= 1: A[2]:= 12:
for n from 3 to 100 do
R:= map(rhs@op, [msolve(y^2=A[n-1]^2, 4*A[n-2])]);
ys:= map(t -> (floor((A[n-1]-t)/(4*A[n-2]))+1)*4*A[n-2]+t, R);
A[n]:= (min(ys)^2-A[n-1]^2)/(4*A[n-2]);
od:
seq(A[i], i=1..100); # Robert Israel, Oct 02 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Zak Seidov, Apr 19 2005
EXTENSIONS
More terms from Robert Israel, Oct 02 2020
STATUS
approved