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A265577
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LCM-transform of Yellowstone permutation A098550.
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2
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1, 2, 3, 2, 3, 2, 5, 7, 1, 1, 5, 1, 1, 2, 1, 1, 1, 1, 3, 11, 13, 1, 1, 1, 1, 1, 1, 17, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 7, 19, 1, 1, 1, 1, 1, 1, 1, 23, 1, 1, 1, 1, 1, 1, 1, 3, 1, 29, 31, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1
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OFFSET
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1,2
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LINKS
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MAPLE
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LCMXfm:=proc(a) local L, i, n, g, b;
L:=nops(a);
g:=Array(1..L, 0); b:=Array(1..L, 0);
b[1]:=a[1]; g[1]:=a[1];
for n from 2 to L do g[n]:=ilcm(g[n-1], a[n]); b[n]:=g[n]/g[n-1]; od;
lprint([seq(b[i], i=1..L)]);
end;
# let t1 contain the first 100 terms of A098550
LCMXfm(t1);
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MATHEMATICA
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LCMXfm[a_List] := Module[{L = Length[a], b, g}, b[1] = g[1] = a[[1]]; b[_] = 0; g[_] = 0; Do[g[n] = LCM[g[n-1], a[[n]]]; b[n] = g[n]/g[n-1], {n, 2, L}]; Array[b, L]];
y[n_ /; n <= 3] := n; y[n_] := y[n] = For[k = 1, True, k++, If[ FreeQ[ Array[y, n-1], k], If[GCD[k, y[n-1]] == 1 && GCD[k, y[n-2]] > 1, Return[k]]]];
Yperm = Array[y, 100];
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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