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Search: id:A117396
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| A117396 |
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Triangle, read by rows, defined by: T(n,k) = (k+1)*T(n,k+1) - Sum_{j=1..n-k-1} T(j,0)*T(n,j+k+1) for n>k with T(n,n)=1 for n>=0. |
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+0 4
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| 1, 1, 1, 1, 2, 1, 1, 5, 3, 1, 1, 17, 11, 4, 1, 1, 77, 51, 19, 5, 1, 1, 437, 291, 109, 29, 6, 1, 1, 2957, 1971, 739, 197, 41, 7, 1, 1, 23117, 15411, 5779, 1541, 321, 55, 8, 1, 1, 204557, 136371, 51139, 13637, 2841, 487, 71, 9, 1, 1, 2018957, 1345971, 504739, 134597
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OFFSET
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0,5
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COMMENT
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Columns equal the partial sums of columns of triangle A092582 for k>0: T(n,k) - T(n-1,k) = A092582(n,k) = number of permutations p of [n] having length of first run equal to k.
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FORMULA
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T(n,k) = k*Sum_{j=k-1..n} j!/(k+1)! for n>=k>0, with T(n,0) = 1 for n>=0. - Paul D. Hanna (pauldhanna(AT)juno.com), Jun 20 2006
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EXAMPLE
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Triangle begins:
1;
1,1;
1,2,1;
1,5,3,1;
1,17,11,4,1;
1,77,51,19,5,1;
1,437,291,109,29,6,1;
1,2957,1971,739,197,41,7,1;
1,23117,15411,5779,1541,321,55,8,1;
1,204557,136371,51139,13637,2841,487,71,9,1; ...
Matrix inverse is:
1;
-1,1;
1,-2,1;
1,1,-3,1;
1,1,1,-4,1;
1,1,1,1,-5,1; ...
Matrix log is the integer triangle A117398:
0;
1,0;
0,2,0;
-1,2,3,0;
-3,4,5,4,0;
-9,14,15,9,5,0;
-33,68,65,34,14,6,0; ...
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PROGRAM
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(PARI) {T(n, k)=if(n<k|k<0, 0, if(n==k, 1, (k+1)*T(n, k+1)-sum(j=1, n-k-1, T(j, 0)*T(n, j+k+1))))} (PARI) /* Definition by Matrix Inverse: * / {T(n, k)=local(M=matrix(n+1, n+1, r, c, if(r>=c, if(r==c+1, -c, 1)))); (M^-1)[n+1, k+1]}
(PARI) T(n, k)=if(n<k|k<0, 0, if(k==0, 1, k*sum(j=k-1, n, j!)/(k+1)!)) - Paul D. Hanna (pauldhanna(AT)juno.com), Jun 20 2006
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CROSSREFS
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Cf. A014288 (column 1), A056199 (column 2), A117397 (column 3), A003422 (row sums), A117398 (matrix log); A092582.
Sequence in context: A062993 A105556 A078920 this_sequence A125860 A125800 A076241
Adjacent sequences: A117393 A117394 A117395 this_sequence A117397 A117398 A117399
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KEYWORD
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nonn,tabl
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), Mar 11 2006
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