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A028258
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Expansion of 1/((1-2*x)*(1-4*x)(1-8*x)(1-16*x)).
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1
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1, 30, 620, 11160, 188976, 3108960, 50434240, 812507520, 13044728576, 209073047040, 3348029967360, 53591377582080, 857645259698176, 13723790036459520, 219592368170516480, 3513571713573027840, 56217898008516427776, 899492372901406310400
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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LINKS
| T. D. Noe, Table of n, a(n) for n=0..100
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FORMULA
| Difference of Gaussian binomial coefficients [ n+1, 4 ]-[ n, 4 ] (n >= 3).
a(0)=1, a(1)=30, a(2)=620, a(3)=11160, a(n)=30*a(n-1)-280*a(n-2)+ 960*a(n-3)-1024*a(n-4) [From Harvey P. Dale, June 18 2011]
a(n)=(2^(n-1)*(2^n-1)*(2^(n+1)-1)*(2^(n+2)-1))/21. [From Harvey P. Dale, June 18 2011]
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MATHEMATICA
| CoefficientList[Series[1/((1-2x)(1-4x)(1-8x)(1-16x)), {x, 0, 50}], x] (* or *) LinearRecurrence[{30, -280, 960, -1024}, {1, 30, 620, 11160}, 50] (* or *) Table[(2^(n-1)(2^n-1)(2^(n+1)-1)(2^(n+2)-1))/21, {n, 20}] (* From Harvey P. Dale, June 18 2011 *)
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CROSSREFS
| Cf. A006516, A016290.
Cf. A006097.
Sequence in context: A051303 A020975 A124099 * A075911 A001719 A004359
Adjacent sequences: A028255 A028256 A028257 * A028259 A028260 A028261
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KEYWORD
| nonn,easy,nice
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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