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Search: id:A128254
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| 1, 1, 1, 1, 3, 1, 1, 5, 5, 1, 1, 7, 12, 7, 1, 1, 9, 22, 22, 9, 1, 1, 11, 35, 50, 35, 11, 11, 13, 51, 95, 95, 51, 13, 1, 1, 15, 70, 161, 210, 161, 70, 15, 1, 1, 17, 92, 252, 406, 406, 252, 92, 17, 1
(list; table; graph; listen)
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OFFSET
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1,5
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COMMENT
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The triangle is bisymmetric, row sums = A045623: (1, 2, 5, 12, 28, 64,...). A114219(signed) * A007318 = A128255.
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FORMULA
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A007318 * A114219, where the latter is signed: {1; 0,1; 0,1,1; 0,-1,2,1; 0,1,-2,3,1;...}. The signed version of A114219 = A097807 * A128229.
T(n,k) = k Binomial[n-2,k-1] + Binomial[n-2,k-2], for 1 <= k <= n. - O. D'Antona, Dec 17 2007
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EXAMPLE
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First few rows of the triangle are:
1;
1, 1;
1, 3, 1;
1, 5, 5, 1;
1, 7, 12, 7, 1;
1, 9, 22, 22, 9, 1;
1, 11, 35, 50, 35, 11, 1;
...
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CROSSREFS
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Cf. A128229, A007318, A114219, A128255, A045623.
Sequence in context: A109128 A113245 A103450 this_sequence A026714 A008288 A144461
Adjacent sequences: A128251 A128252 A128253 this_sequence A128255 A128256 A128257
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KEYWORD
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nonn,tabl
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AUTHOR
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Gary W. Adamson (qntmpkt(AT)yahoo.com), Feb 20 2007
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EXTENSIONS
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Typo in sequence corrected by O. D'Antona (dantona(AT)dico.unimi.it), Dec 17 2007
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