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Search: id:A159697
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| A159697 |
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a(0)=9, a(n)=2*a(n-1)+2^(n-1) for n>0 . |
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+0
3
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| 9, 19, 40, 84, 176, 368, 768, 1600, 3328, 6912, 14336, 29696, 61440, 126976, 262144, 540672, 1114112, 2293760, 4718592, 9699328, 19922944, 40894464, 83886080, 171966464, 352321536, 721420288, 1476395008, 3019898880
(list; graph; listen)
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OFFSET
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0,1
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COMMENT
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Diagonal of triangles A062111, A152920 .
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FORMULA
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a(n)=Sum_{k=0..n} (k+9)*binomial(n,k).
a(n) = (18+n)*2^(n-1) = 4*a(n-1)-4*a(n-2). G.f.: (9-17x)/(1-2x)^2. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 20 2009]
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EXAMPLE
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a(0)=9, a(1)=2*9+1=19, a(2)=2*19+2=40, a(3)=2*40+4=84, a(4)=2*84+8=176, ...
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CROSSREFS
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Cf. A000079, A001787, A001792, A045623, A045891, A034007, A111297, A159694, A159695, A159696
Sequence in context: A157034 A145958 A039299 this_sequence A014005 A058510 A043122
Adjacent sequences: A159694 A159695 A159696 this_sequence A159698 A159699 A159700
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KEYWORD
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easy,nonn
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AUTHOR
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Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Apr 20 2009
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EXTENSIONS
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More terms from Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Apr 30 2009
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