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A242357
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Crescendo trapezoidal.
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6
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1, 1, 2, 2, 1, 1, 2, 3, 3, 3, 2, 1, 1, 2, 3, 4, 4, 4, 4, 3, 2, 1, 1, 2, 3, 4, 5, 5, 5, 5, 5, 4, 3, 2, 1, 1, 2, 3, 4, 5, 6, 6, 6, 6, 6, 6, 5, 4, 3, 2, 1, 1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 6, 5, 4, 3, 2, 1, 1, 2, 3, 4, 5, 6, 7, 8, 8, 8, 8, 8, 8, 8, 8, 7
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,3
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COMMENTS
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a(A000326(n)) = a(A143689(n-1)) = 1;
for all n: a(k) = n, A104249(n-1) <= k <= A005448(n).
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LINKS
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Reinhard Zumkeller, Table of n, a(n) for n = 1..1001
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EXAMPLE
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. Initial values
. seen trapezoidal: 666666
. 55555 5......5
. 4444 4.....4 4........4
. 333 3....3 3.......3 3..........3
. 22 2...2 2......2 2.........2 2............2
. 1 1..1 1.....1 1........1 1...........1 1..............1 .
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MATHEMATICA
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Table[Join[Range[n-1], PadRight[{}, n, n], Range[n-1, 1, -1]], {n, 9}]//Flatten (* Harvey P. Dale, Oct 23 2020 *)
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PROG
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(Haskell)
import Data.List (inits)
a242357 n = a242357_list !! (n-1)
a242357_list = concatMap f $ tail $ inits [1..] where
f us = (init us) ++ (take v [v, v ..]) ++ vs
where (v:vs) = reverse us
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CROSSREFS
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Cf. A004737.
Sequence in context: A004739 A156282 A203776 * A120423 A113137 A220603
Adjacent sequences: A242354 A242355 A242356 * A242358 A242359 A242360
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller, May 11 2014
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STATUS
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approved
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