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 A114800 Octuple factorial, 8-factorial, n!8, n!!!!!!!!. 13
 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 20, 33, 48, 65, 84, 105, 128, 153, 360, 627, 960, 1365, 1848, 2415, 3072, 3825, 9360, 16929, 26880, 39585, 55440, 74865, 98304, 126225, 318240, 592515, 967680, 1464645, 2106720, 2919735, 3932160, 5175225, 13366080 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Harvey P. Dale, Table of n, a(n) for n = 0..1000 Eric Weisstein's World of Mathematics, Multifactorial. FORMULA a(n) = 1 for n<1, else a(n) = n*a(n-8). EXAMPLE a(10) = 10 * a(10-8) = 10 * a(2) = 10 * 2 = 20. a(20) = 20 * a(20-8) = 20 * a(12) = 20 * (12*a(12-8)) = 20 * 12 * a(4) = 20 * 12 * 4 = 960. a(30) = 30 * a(30-8) = 30 * a(22) = 30 * (22*a(22-8)) = 30 * 22 * a(14) = 30 * 22 * (14*a(14-8)) = 30 * 22 * 14 * 6 = 55440. MAPLE A114800 := proc(n)     option remember;     if n < 1 then         1;     else         n*procname(n-8) ;     end if; end proc: seq(A114800(n), n=0..40) ; # R. J. Mathar, Jun 23 2014 MATHEMATICA Table[Times@@Range[n, 1, -8], {n, 0, 50}] (* Harvey P. Dale, Feb 17 2018 *) PROG (PARI) a(n)=if(n<1, 1, n*a(n-8)); vector(50, n, n--; a(n) ) \\ G. C. Greubel, Aug 21 2019 (MAGMA) b:=func< n | n le 8 select n else n*Self(n-8) >; [1] cat [b(n): n in [1..50]]; // G. C. Greubel, Aug 21 2019 (Sage) def a(n):     if (n<1): return 1     else: return n*a(n-8) [a(n) for n in (0..50)] # G. C. Greubel, Aug 21 2019 (GAP) a:= function(n)     if n<1 then return 1;     else return n*a(n-8);     fi;   end; List([0..50], n-> a(n) ); # G. C. Greubel, Aug 21 2019 CROSSREFS Cf. A000142, A006882, A007661, A007662, A085157, A085158. Sequence in context: A326106 A180412 A290951 * A079170 A330927 A319387 Adjacent sequences:  A114797 A114798 A114799 * A114801 A114802 A114803 KEYWORD easy,nonn AUTHOR Jonathan Vos Post, Feb 18 2006 STATUS approved

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Last modified August 3 13:49 EDT 2020. Contains 336198 sequences. (Running on oeis4.)