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A081038
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3rd binomial transform of (1,2,0,0,0,0,0,0....).
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13
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1, 5, 21, 81, 297, 1053, 3645, 12393, 41553, 137781, 452709, 1476225, 4782969, 15411789, 49424013, 157837977, 502211745, 1592728677, 5036466357, 15884240049, 49977243081, 156905298045, 491636600541, 1537671920841
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..400
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FORMULA
| G.f.: (1-x)/(1-3*x)^2.
a(n)=6*a(n-1)-9*a(n-2), with a(0)=1, a(1)=5
a(n)=(2*n+3)*3^(n-1)
a(n)=sum(k=0..n, (k+1)*2^k*binomial(n, k)).
Equals 2*A086972(n) - 1. - Lambert Herrgesell (zero815(AT)googlemail.com), Feb 10 2008
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PROG
| (MAGMA) [(2*n+3)*3^(n-1): n in [0..30]]; // Vincenzo Librandi, Jun 09 2011
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CROSSREFS
| Cf. A001792, A081039, A081040.
First differences of A027471.
Sequence in context: A027172 A186244 A029870 * A153008 A051196 A094834
Adjacent sequences: A081035 A081036 A081037 * A081039 A081040 A081041
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Mar 03 2003
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