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A242357 Crescendo trapezoidal. 6
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)
OFFSET

1,3

COMMENTS

a(A000326(n)) = a(A143689(n-1)) = 1;

for all n: a(k) = n, A104249(n-1) <= k <= A005448(n).

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..1001

EXAMPLE

. 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 .

PROG

(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

CROSSREFS

Cf. A004737.

Sequence in context: A004739 A156282 A203776 * A120423 A113137 A220603

Adjacent sequences:  A242354 A242355 A242356 * A242358 A242359 A242360

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, May 11 2014

STATUS

approved

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Last modified December 13 01:33 EST 2017. Contains 295954 sequences.