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Search: id:A016290
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| A016290 |
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Expansion of 1/((1-2x)(1-4x)(1-8x)). |
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+0
5
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| 1, 14, 140, 1240, 10416, 85344, 690880, 5559680, 44608256, 357389824, 2861214720, 22898104320, 183218384896, 1465881288704, 11727587164160, 93822844764160, 750591347982336, 6004765143465984, 48038258586419200
(list; graph; listen)
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OFFSET
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0,2
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LINKS
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T. D. Noe, Table of n, a(n) for n=0..100
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FORMULA
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Difference of Gaussian binomial coefficients [ n+1, 3 ]-[ n, 3 ] (n >= 2).
a(n)=(2^n-6*4^n+8*8^n)/3 - Jim Buddenhagen (jbuddenh(AT)gmail.com), Dec 14 2003
a(n)=sum{0<=i,j,k,<=n, i+j+k=n, 2^i*4^j*8^k}. - Hieronymus Fischer (Hieronymus.Fischer(AT)gmx.de), Jun 25 2007
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MAPLE
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[ seq(GBC(n+1, 3, 2)-GBC(n, 3, 2), n=2..30) ]; # produces A016290 (cf. A006516).
seq((2^n-6*4^n+8*8^n)/3, n=1..20);
seq(binomial(2^n, 3)/4, n=2..20); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Feb 22 2008
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CROSSREFS
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Cf. A006516.
Sequence in context: A021044 A121034 A125402 this_sequence A003457 A016241 A131583
Adjacent sequences: A016287 A016288 A016289 this_sequence A016291 A016292 A016293
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KEYWORD
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nonn,nice,easy
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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