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A278240
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Least number with the prime signature of 2^n - 1.
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3
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1, 2, 2, 6, 2, 12, 2, 30, 6, 30, 6, 420, 2, 30, 30, 210, 2, 840, 2, 4620, 60, 210, 6, 60060, 30, 30, 30, 30030, 30, 60060, 2, 2310, 210, 30, 210, 38798760, 6, 30, 210, 1021020, 6, 180180, 30, 510510, 30030, 210, 30, 446185740, 6, 510510, 2310, 510510, 30, 240240, 30030, 9699690, 210, 30030, 6, 1203362940780, 2, 30, 60060, 510510, 30, 19399380, 6, 510510, 210
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listen;
history;
text;
internal format)
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OFFSET
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1,2
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LINKS
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FORMULA
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MATHEMATICA
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Table[Times @@ MapIndexed[(Prime@ First@ #2)^#1 &, #] &@ If[Length@ # == 1 && #[[1, 1]] == 1, {0}, Reverse@ Sort@ #[[All, -1]]] &@ FactorInteger[2^n - 1], {n, 69}] (* Michael De Vlieger, Nov 21 2016 *)
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PROG
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(PARI)
allocatemem(2^30);
for(n=1, 256, write("b278240.txt", n, " ", A278240(n)));
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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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