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Search: id:A156141
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| 2, 1, 1, 1, 4, 1, 1, 14, 14, 1, 1, 46, 116, 46, 1, 1, 172, 772, 772, 172, 1, 1, 834, 5160, 8800, 5160, 834, 1, 1, 5280, 39594, 90260, 90260, 39594, 5280, 1, 1, 40814, 361086, 981104, 1288040, 981104, 361086, 40814, 1, 1, 363884, 3801180, 12088796
(list; table; graph; listen)
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OFFSET
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0,1
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COMMENT
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Row sums are 2*A001147(n).
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LINKS
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E. W. Weisstein, Second-Order Eulerian Triangle
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FORMULA
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T(n,0)=T(n,n) =1, n>=1.
T(n,k)= A008517(n,k+1)+A008517(n,n+1-k), n>1, 0<k<n.
T(n,k)= T(n,n-k) .
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EXAMPLE
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{2},
{1, 1},
{1, 4, 1},
{1, 14, 14, 1},
{1, 46, 116, 46, 1},
{1, 172, 772, 772, 172, 1},
{1, 834, 5160, 8800, 5160, 834, 1},
{1, 5280, 39594, 90260, 90260, 39594, 5280, 1},
{1, 40814, 361086, 981104, 1288040, 981104, 361086, 40814, 1},
{1, 363884, 3801180, 12088796, 18205564, 18205564, 12088796, 3801180, 363884, 1},
{1, 3630826, 44557888, 167513072, 283669904, 310714768, 283669904, 167513072, 44557888, 3630826, 1}
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MATHEMATICA
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e[n_, 0] := 1;
e[n_, k_] := 0 /; k >= n;
e[n_, k_] := (k + 1)e[n - 1, k] + (2n - k - 1)e[n - 1, k - 1];
Table[Table[e[n, k] + e[n, n - k], {k, 0, n}], {n, 0, 10}];
Flatten[%]
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CROSSREFS
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Cf. A008517
Sequence in context: A010121 A157114 A156786 this_sequence A157113 A139320 A118106
Adjacent sequences: A156138 A156139 A156140 this_sequence A156142 A156143 A156144
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KEYWORD
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nonn,tabl
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AUTHOR
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Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Feb 04 2009
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EXTENSIONS
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Definition simplified by the Associate Editors of the OEIS Sep 17 2009
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