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A139308
Lucky numbers that are pure (perfect) powers with exponent greater than 2.
1
729, 2187, 29791, 50625, 50653, 83521, 130321, 132651, 166375, 185193, 226981, 300763, 707281, 804357, 823543, 1295029, 1860867, 1874161, 2685619, 3176523, 4782969, 5545233, 5764801, 7189057, 9393931, 12977875, 13845841, 16194277
OFFSET
1,1
COMMENTS
Intersection of A000959 and A076467.
LINKS
Kevin P. Thompson, Table of n, a(n) for n = 1..113 (terms < 10^10 with terms 1..94 from Giovanni Resta)
EXAMPLE
a(1) = 729 = 3^6 and 729 is lucky, i.e., A000959(118) = 729.
MATHEMATICA
t = 2 Range@ 10000000 - 1; f[n_] := Block[{k = t[[n]]}, t = Delete[t, Table[{k}, {k, k, Length@t, k}]]]; Do[f@n, {n, 2, 1000000}]; fQ[n_] := ! IntegerQ@ Log[2, n] && GCD @@ Last /@ FactorInteger@n > 2; Select[t, fQ] (* Robert G. Wilson v, Oct 16 2010 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Walter Kehowski, Jun 07 2008
EXTENSIONS
a(16)-a(28) from Robert G. Wilson v, Oct 16 2010
STATUS
approved