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%I #10 Aug 26 2019 16:28:18
%S 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,
%T 36,31,5,5,32,840,18,18,180,90,10,10,42,280,6,6,38,264,21,21,210,1540,
%U 26,26,52,10920,9,9,1320,780,30,30,300,6,6,6,174,570,11,11,290,549,9,9
%N Row 4 of array in A105272.
%p 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
%t k = 4;
%t Table[fp = {};
%t For[col = k, col > 0, col--,
%t For[row = 0, col + row*k <= n, row++,
%t AppendTo[fp, col + row*k]]];
%t LCM @@ Length /@ First[FindPermutation[Range[n], fp]], {n, k,
%t 76}] (* _Robert Price_, Aug 26 2019 *)
%K nonn
%O 4,1
%A _N. J. A. Sloane_, Aug 10 2008, based on email from Samuel Minter (abulsme(AT)abulsme.com0, May 08 2008, Aug 10 2008
%E Extended beyond a(14) by _R. J. Mathar_, Aug 11 2008
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