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A086972
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n*3^(n-1) + (3^n+1)/2.
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2
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1, 3, 11, 41, 149, 527, 1823, 6197, 20777, 68891, 226355, 738113, 2391485, 7705895, 24712007, 78918989, 251105873, 796364339, 2518233179, 7942120025, 24988621541, 78452649023, 245818300271, 768835960421, 2400651060089
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Binomial transform of A057711 (without leading zero). Second binomial transform of (1,1,3,3,5,5,7,7,9,9,11,11,...).
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..400
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FORMULA
| G.f.: (1-4*x+5*x^2)/((1-x)*(1-3*x)^2)).
a(n)=A027471(n)+A007051(n).
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PROG
| (MAGMA) [n*3^(n-1) + (3^n+1)/2: n in [0..30]]; // Vincenzo Librandi, Jun 09 2011
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CROSSREFS
| Equals (1/2) [A081038(n) + 1].
Sequence in context: A073622 A181863 A075276 * A077831 A032952 A001835
Adjacent sequences: A086969 A086970 A086971 * A086973 A086974 A086975
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Jul 26 2003
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