OFFSET
0,2
FORMULA
a(n) = denominator(r(n)) where r(n) = Sum_{j=0..n} j!^2 / (2^j*floor(j/2))^4.
a(n) = 4^A327492(n). - Kevin Ryde, May 31 2022
PROG
(SageMath)
@cached_function
def A327496(n):
if n == 0: return 1
r = valuation(n, 2) if 4.divides(n) else n % 2 + 1
return 4^r * A327496(n-1)
print([A327496(n) for n in (0..19)])
(PARI) a(n) = 1 << (4*n - 2*hammingweight(n>>1)); \\ Kevin Ryde, May 31 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Peter Luschny, Sep 29 2019
STATUS
approved