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A106580
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Triangle T(n,k) (n>=0, 0<=k<=n) read by rows: T(n,0)=1, T(n,k) = T(n,k-1) + Sum_{i >= 1} T(n-2i,k-i).
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3
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1, 1, 1, 1, 2, 2, 1, 2, 3, 3, 1, 2, 5, 7, 7, 1, 2, 5, 9, 12, 12, 1, 2, 5, 13, 22, 29, 29, 1, 2, 5, 13, 26, 41, 53, 53, 1, 2, 5, 13, 34, 65, 101, 130, 130, 1, 2, 5, 13, 34, 73, 129, 194, 247, 247, 1, 2, 5, 13, 34, 89, 185, 322, 481, 611, 611, 1, 2, 5, 13, 34, 89, 201, 386, 645, 945, 1192, 1192, 1, 2, 5, 13, 34, 89, 233, 514, 973, 1613, 2354, 2965, 2965
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 0,5
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COMMENTS
| Next term is previous term + terms directly above you on a vertical line.
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EXAMPLE
| 1; 1,1; 1,2,2; 1,2,3,3; 1,2,5,7,7; ...
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MAPLE
| A106580 := proc(n, k) option remember ; if k =0 then 1 ; else A106580(n, k-1)+add(A106580(n-2*i, k-i), i=1..min(k, floor(n/2), n-k)) ; fi ; end: for n from 0 to 12 do for k from 0 to n do printf("%d, ", A106580(n, k)) ; od ; od ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 02 2007
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CROSSREFS
| An intermingling of two independent triangles, A106595 and A106596.
Sequence in context: A054711 A193738 A134658 * A165915 A043276 A064742
Adjacent sequences: A106577 A106578 A106579 * A106581 A106582 A106583
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KEYWORD
| nonn,tabl,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), May 30 2005
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EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 02 2007
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