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Search: id:A026384
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| A026384 |
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Sum{T(i,j)}, 0<=j<=i, 0<=i<=n, where T is the array in A026374. |
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+0
1
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| 1, 3, 8, 18, 43, 93, 218, 468, 1093, 2343, 5468, 11718, 27343, 58593, 136718, 292968, 683593, 1464843, 3417968, 7324218, 17089843, 36621093, 85449218, 183105468, 427246093, 915527343, 2136230468, 4577636718, 10681152343
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OFFSET
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0,2
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COMMENT
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Partial sums of A026383. Number of lattice paths from (0,0) that do not go to right of the line x=n, using the steps U=(1,1), D=(1,-1) and, at levels ...,-4,-2,0,2,4,..., also H=(2,0). Example: a(2)=8 because we have the empty path, U, D, UU, UD, DD, DU, and H. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Feb 18 2004
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FORMULA
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G.f.: [1+2x]/[(1-x)(1-5x^2)]. - R. Stephan, Apr 30 2004
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MAPLE
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a[0]:=0:a[1]:=1:for n from 2 to 100 do a[n]:=5*a[n-2]+3 od: seq(a[n], n=1..29); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 17 2008
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CROSSREFS
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Cf. A026383.
Sequence in context: A066425 A026679 A026756 this_sequence A066143 A110045 A108931
Adjacent sequences: A026381 A026382 A026383 this_sequence A026385 A026386 A026387
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KEYWORD
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nonn
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AUTHOR
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Clark Kimberling (ck6(AT)evansville.edu)
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