OFFSET
0,2
COMMENTS
See A129065 for the M. Bruschi et al. reference.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..250
FORMULA
a(n) = A129065(n+2, 2), n >= 0.
MATHEMATICA
T[n_, k_]:= T[n, k]= If[k<0 || k>n, 0, If[n==0, 1, 2*(n-1)^2*T[n-1, k] - 4*Binomial[n-1, 2]^2*T[n-2, k] +T[n-1, k-1] ]]; (* T=A129065 *)
A129460[n_]:= T[n+2, 2];
Table[A129460[n], {n, 0, 40}] (* G. C. Greubel, Feb 08 2024 *)
PROG
(Magma)
function T(n, k) // T = A129065
if k lt 0 or k gt n then return 0;
elif n eq 0 then return 1;
else return 2*(n-1)^2*T(n-1, k) - 4*Binomial(n-1, 2)^2*T(n-2, k) + T(n-1, k-1);
end if;
end function;
A129460:= func< n | T(n+2, 2) >;
[A129460(n): n in [0..20]]; // G. C. Greubel, Feb 08 2024
(SageMath)
@CachedFunction
def T(n, k): # T = A129065
if (k<0 or k>n): return 0
elif (n==0): return 1
else: return 2*(n-1)^2*T(n-1, k) - 4*binomial(n-1, 2)^2*T(n-2, k) + T(n-1, k-1)
def A129460(n): return T(n+2, 2)
[A129460(n) for n in range(41)] # G. C. Greubel, Feb 08 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, May 04 2007
STATUS
approved