OFFSET
0,3
COMMENTS
Unlike the factorial number n!, but like A356858(n), a(n) does not have trailing zeros.
FORMULA
a(n) = Product_{k=1..n} A045572(k).
MATHEMATICA
Table[Product[2*k+2*Floor[(k-3)/4]+1, {k, n}], {n, 0, 20}]
PROG
(PARI) f(n) = 2*n - 1 + (n+1)\4 * 2; \\ A045572
a(n) = prod(k=1, n, f(k)); \\ Michel Marcus, Dec 10 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Stefano Spezia, Dec 09 2022
STATUS
approved