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A081541 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. 2
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; text; internal format)
OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..10000

EXAMPLE

Triangle begins:

0;

2,1;

32,31,21;

432,431,421,321;

5432,5431,5421,5321,4321;

65432,65431,...

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, Jul 15 2007

MATHEMATICA

Table[Reverse[FromDigits/@Table[Drop[Range[k, 1, -1], {n}], {n, 1, k}]], {k, 8}]//Flatten (* Harvey P. Dale, Aug 27 2016 *)

CROSSREFS

Cf. A081539, A081540, A081542.

Sequence in context: A074011 A054235 A016547 * A344105 A323751 A113465

Adjacent sequences:  A081538 A081539 A081540 * A081542 A081543 A081544

KEYWORD

base,nonn,tabl

AUTHOR

Amarnath Murthy, Mar 29 2003

EXTENSIONS

More terms from R. J. Mathar, Jul 15 2007

STATUS

approved

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Last modified September 21 20:10 EDT 2021. Contains 347598 sequences. (Running on oeis4.)