editing

approved

a(n) = Product_{j=0..n} j!!!!.

a(n) = Product_{j=0..n} A007662(j).

a(n) = n!!!! * a(n-1) where a(0) = 1, a(1) = 1 and n >= 2.

a(n) = Prod[i=0 to n] n!!!!. a(n) = Prod[i=0 to n] A007662(n). a(n) = n!!!! * a(n-1) where a(0) = 1, a(1) = 1 and n >= 2. a(n) = n*(n-4)!!!! * a(n-1) where a(0) = 1, a(1) = 1, a(2) = 2.

approved

editing

_Jonathan Vos Post (jvospost3(AT)gmail.com), _, Feb 18 2006

easy,nonn,new

Jonathan Vos Post (jvospost2jvospost3(AT)yahoogmail.com), Feb 18 2006

Eric W. Weisstein, 's World of Mathematics, <a href="http://mathworld.wolfram.com/Multifactorial.html">Multifactorial.</a>

easy,nonn,new

Cf. A006882, A007662, A114477, A000178, A114347.

easy,nonn,new

a(n) = PRODUCTProd[i=0 to n] n!!!!. a(n) = PRODUCTProd[i=0 to n] A007662(n). a(n) = n!!!! * a(n-1) where a(0) = 1, a(1) = 1 and n >= 2. a(n) = n*(n-4)!!!! * a(n-1) where a(0) = 1, a(1) = 1, a(2) = 2.

easy,nonn,new

Cumulative product of quadruple factorial A007662.

1, 1, 2, 6, 24, 120, 1440, 30240, 967680, 43545600, 5225472000, 1207084032000, 463520268288000, 271159356948480000, 455547719673446400000, 1578472848668491776000000, 9698137182219213471744000000

0,3

Eric W. Weisstein, <a href="http://mathworld.wolfram.com/Multifactorial.html">Multifactorial.</a>

a(n) = PRODUCT[i=0 to n] n!!!!. a(n) = PRODUCT[i=0 to n] A007662(n). a(n) = n!!!! * a(n-1) where a(0) = 1, a(1) = 1 and n >= 2. a(n) = n*(n-4)!!!! * a(n-1) where a(0) = 1, a(1) = 1, a(2) = 2.

a(10) = 1!!!! * 2!!!! * 3!!!! * 4!!!! * 5!!!! * 6!!!! * 7!!!! * 8!!!! * 9!!!! * 10!!!! = 1 * 2 * 3 * 4 * 5 * 12 * 21 * 32 * 45 * 120 = 5225472000 = 2^13 * 3^6 * 5^3 * 7.

Cf. A006882, A007662, A114477, A114347.

easy,nonn

Jonathan Vos Post (jvospost2(AT)yahoo.com), Feb 18 2006

approved