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A081541
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Triangle read by rows: the n-th row contains n numbers sorted in decreasing value, each build by dropping a different number from the sequence [n,n-1,n-2,....,1] and concatenating the n-1 others. By definition the first row contains 0.
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0, 2, 1, 32, 31, 21, 432, 431, 421, 321, 5432, 5431, 5421, 5321, 4321, 65432, 65431, 65421, 65321, 64321, 54321, 765432, 765431, 765421, 765321, 764321, 754321, 654321, 8765432, 8765431, 8765421, 8765321, 8764321, 8754321, 8654321, 7654321
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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EXAMPLE
| 0; 2,1; 32,31,21; 432,431,421,321,5432,5431,5421,5321,4321; 65432,65431,
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MAPLE
| conca := proc(S) local resul, d, i ; resul := 0 ; for i from 1 to nops(S) do d := ilog10(op(i, S))+1 ; resul := resul*10^d+op(i, S) ; od ; resul ; end: A081541 := proc(row) local a, p, i; if row =1 then RETURN([0]) ; fi ; a := [] ; p := [seq(row+1-i, i=1..row)] ; for i from 1 to row do a := [op(a), conca(subsop(i=NULL, p))] ; od: sort(a, `>`)[1..row] ; end: seq(op(A081541(n)), n=1..10) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 15 2007
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CROSSREFS
| Cf. A081539, A081540, A081542.
Sequence in context: A074011 A054235 A016547 * A113465 A113456 A205445
Adjacent sequences: A081538 A081539 A081540 * A081542 A081543 A081544
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KEYWORD
| base,nonn,tabl
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AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 29 2003
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EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 15 2007
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