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A181161
Numerator in abs(binomial(-1/8,n)).
0
1, 1, 9, 51, 1275, 8415, 115005, 805035, 45886995, 331406075, 4838528695, 35629165845, 1056998586735, 7886835608715, 118302534130725, 891212423784795, 107836703277960195, 818290277815109715
OFFSET
0,3
FORMULA
a(n) = 2^(e_2((2*n)!)-n)/n! * Product[8k+1,{k,0,n-1}] where e_2((2n)!) is the highest power of 2 that divides (2*n)! (sequence A005187)
MATHEMATICA
w[n_] := Numerator[Binomial[(-1/8, n](-1)^n]
Table[w1[n], {n, 0, 12}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Emanuele Munarini, Jan 25 2011
STATUS
approved