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 A113296 Cumulative product of double factorial A006882. 0
 1, 1, 2, 6, 48, 720, 34560, 3628800, 1393459200, 1316818944000, 5056584744960000, 52563198423859200000, 2422112183371431936000000, 327312129899898454671360000000, 211155601241022491077587763200000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Eric Weisstein's World of Mathematics, Double Factorial. FORMULA a(n) = Prod[i=0 to n] n!!. a(n) = n!! * a(n-1) where a(0) = 0, a(1) = 1 and n >= 2. a(n) = n*(n-2)!! * a(n-1) where a(0) = 0, a(1) = 1 and n >= 2. EXAMPLE a(10) = 1!! * 2!! * 3!! * 4!! * 5!! * 6!! * 7!! * 8!! * 9!! * 10!! = 1 * 2 * 3 * 8 * 15 * 48 * 105 * 384 * 945 * 3840 = 5056584744960000 = 2^23 x 3^9 x 5^4 x 7^2. CROSSREFS Cf. A006882. Sequence in context: A175430 A129464 A003053 * A063744 A141609 A096313 Adjacent sequences:  A113293 A113294 A113295 * A113297 A113298 A113299 KEYWORD easy,nonn AUTHOR Jonathan Vos Post, Feb 18 2006 STATUS approved

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