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A084980
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Triangle of (multi)factorials: n-th row is (n+1)!!... {n "!"s}, (n+1)!... {n-1 "!"s}, ..., (n+1)!.
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0
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2, 3, 6, 4, 8, 24, 5, 10, 15, 120, 6, 12, 18, 48, 720, 7, 14, 21, 28, 105, 5040, 8, 16, 24, 32, 80, 384, 40320, 9, 18, 27, 36, 45, 162, 945, 362880, 10, 20, 30, 40, 50, 120, 280, 3840, 3628800, 11, 22, 33, 44, 55, 66, 231, 880, 10395, 39916800, 12, 24, 36, 48, 60, 72, 168
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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LINKS
| Eric Weisstein's World of Mathematics, Link to Factorial section of The World of Mathematics.
Eric Weisstein's World of Mathematics, Link to Multifactorial section of The World of Mathematics.
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EXAMPLE
| Triangle begins
Row 1: 2! = 2
Row 2: 3!! = 3*1 = 3, 3! = 3*2*1 = 6
Row 3: 4!!! = 4*1 = 4, 4!! = 4*2 = 8, 4! = 4*3*2*1 = 24,
Row 4: 5!!!! = 5*1 = 5, 5!!! = 5*2 = 10, 5!! = 5*3 = 15, 5! = 5*4*3*2*1 = 120,
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CROSSREFS
| Cf. A000142 (n!), A006882 (n!!), A007661 (n!!!), A007662 (n!!!!).
Sequence in context: A052330 A059900 A123664 * A101369 A125147 A103864
Adjacent sequences: A084977 A084978 A084979 * A084981 A084982 A084983
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KEYWORD
| nonn,tabl
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AUTHOR
| Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jul 16 2003
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