OFFSET
0,2
FORMULA
MATHEMATICA
ser := Series[(1 - Sqrt[1 - 4 x^2] - 4 x^2 (1 - x - Sqrt[1 - 4 x^2]))/(2 x^2 (1 - 4 x^2)^(3/2)), {x, 0, 22}]; Table[n! Coefficient[ser, x, n], {n, 0, 20}]
Table[(1+n)Floor[1+n/2](n!/Floor[1+n/2]!)^2, {n, 0, 30}] (* Harvey P. Dale, Oct 01 2023 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Dec 04 2019
STATUS
approved