OFFSET
0,3
FORMULA
a(n) ~ Pi * n^2 /4. - Vaclav Kotesovec, Apr 03 2024
EXAMPLE
a(3) = 7: (3/2) * (5/4) * (7/6) * (9/8) * (11/10) * (13/12) * (15/14) = 6435 / 2048 = 3.14208984375 > 3.
MATHEMATICA
a[n_] := For[k = 1, True, k++, If[(2 k + 1)!!/(2 k)!! >= n, Return[k]]]; Table[a[n], {n, 0, 55}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Apr 03 2024
STATUS
approved