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 A120280 Row 4 of array in A105272. 3
 2, 2, 4, 7, 3, 3, 8, 10, 6, 6, 20, 4, 4, 4, 132, 30, 3, 3, 24, 252, 10, 10, 238, 26, 14, 14, 36, 31, 5, 5, 32, 840, 18, 18, 180, 90, 10, 10, 42, 280, 6, 6, 38, 264, 21, 21, 210, 1540, 26, 26, 52, 10920, 9, 9, 1320, 780, 30, 30, 300, 6, 6, 6, 174, 570, 11, 11, 290, 549, 9, 9 (list; graph; refs; listen; history; text; internal format)
 OFFSET 4,1 LINKS Table of n, a(n) for n=4..73. MAPLE abulsme := proc(L, k) local r, p, dangl, R, c; R := ceil(nops(L)/k) ; p := [] ; dangl := nops(L) mod k ; for c from k to 1 by -1 do for r from 1 to R do if r = R and dangl>0 and c>dangl then break; fi; p := [op(p), op(c+k*(r-1), L) ] ; od: od: RETURN(p) ; end: isSrtd := proc(L) for i from 1 to nops(L)-1 do if op(i, L) > op(i+1, L) then RETURN(false) ; fi; od: RETURN(true) ; end: A105272 := proc(n, k) local a, L; L := [seq(i, i=1..n)] ; a := 1 ; L := abulsme(L, k) ; while not isSrtd(L) do L := abulsme(L, k) ; a := a+1 ; od: RETURN(a) ; end: A120280 := proc(n) A105272(n, 4) ; end: for n from 4 to 90 do printf("%d, ", A120280(n)) ; od: # R. J. Mathar, Aug 11 2008 MATHEMATICA k = 4; Table[fp = {}; For[col = k, col > 0, col--, For[row = 0, col + row*k <= n, row++, AppendTo[fp, col + row*k]]]; LCM @@ Length /@ First[FindPermutation[Range[n], fp]], {n, k, 76}] (* Robert Price, Aug 26 2019 *) CROSSREFS Sequence in context: A350764 A249758 A157470 * A212362 A209142 A115754 Adjacent sequences: A120277 A120278 A120279 * A120281 A120282 A120283 KEYWORD nonn AUTHOR N. J. A. Sloane, Aug 10 2008, based on email from Samuel Minter (abulsme(AT)abulsme.com0, May 08 2008, Aug 10 2008 EXTENSIONS Extended beyond a(14) by R. J. Mathar, Aug 11 2008 STATUS approved

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Last modified December 5 05:37 EST 2023. Contains 367575 sequences. (Running on oeis4.)