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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 . MATHEMATICA Table[Join[Range[n-1], PadRight[{}, n, n], Range[n-1, 1, -1]], {n, 9}]//Flatten (* Harvey P. Dale, Oct 23 2020 *) 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 April 17 13:31 EDT 2021. Contains 343063 sequences. (Running on oeis4.)