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A126063 Triangle read by rows: see A128196 for definition. 2
1, 1, 2, 3, 6, 4, 15, 30, 20, 8, 105, 210, 140, 56, 16, 945, 1890, 1260, 504, 144, 32, 10395, 20790, 13860, 5544, 1584, 352, 64, 135135, 270270, 180180, 72072, 20592, 4576, 832, 128, 2027025, 4054050, 2702700, 1081080, 308880, 68640, 12480, 1920, 256 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Ivan Neretin, Rows n = 0..100, flattened

P. Luschny, Variants of Variations.

FORMULA

T(n,k) = 2^k*(2n - 1)!!/(2k - 1)!!. - Ivan Neretin, May 13 2015

EXAMPLE

Triangle begins:

...........1.

...........1,.......2

...........3,.......6,.......4.

..........15,......30,......20,.......8

.........105,.....210,.....140,......56,.....16

.........945,....1890,....1260,.....504,....144,....32

.......10395,...20790,...13860,....5544,...1584,...352,....64

......135135,..270270,..180180,...72072,..20592,..4576,...832,..128

MAPLE

A126063 := (n, k) -> 2^k*doublefactorial(2*n-1)/ doublefactorial(2*k-1); seq(print(seq(A126063(n, k), k=0..n)), n=0..7); # Peter Luschny, Dec 20 2012

MATHEMATICA

Flatten[Table[2^k (2n - 1)!!/(2k - 1)!!, {n, 0, 8}, {k, 0, n}]] (* Ivan Neretin, May 11 2015 *)

CROSSREFS

Sequence in context: A227296 A231263 A231451 * A214352 A248090 A229774

Adjacent sequences:  A126060 A126061 A126062 * A126064 A126065 A126066

KEYWORD

nonn,tabl,easy

AUTHOR

N. J. A. Sloane, Feb 28 2007

STATUS

approved

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Last modified September 22 00:25 EDT 2017. Contains 292326 sequences.