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A182302 Composite numbers that are not perfect powers whose prime factors have equal numbers of bits. 2
6, 12, 18, 24, 35, 48, 54, 72, 96, 108, 143, 162, 175, 192, 245, 288, 323, 384, 391, 432, 437, 486, 493, 527, 551, 589, 648, 667, 713, 768, 864, 875, 899, 972, 1152, 1458, 1517, 1536, 1573, 1591, 1715, 1739, 1763, 1859, 1927, 1944, 1961, 2021, 2173, 2183, 2257 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Arkadiusz Wesolowski, Table of n, a(n) for n = 1..10000
EXAMPLE
35 = 5*7 -> 101*111, therefore 35 is a term.
36 = 6^2 -> 10*10*11*11, therefore 36 is not a term.
MATHEMATICA
lst1 = {}; lst2 = {}; r = 2257; Do[b = IntegerDigits[FactorInteger[n], 2]; If[! PrimeQ[n] && Length[b[[-1, 1]]] == Length[b[[1, 1]]], AppendTo[lst1, n]], {n, 4, r}]; lst2 = Complement[lst1, Union[Flatten[Table[n^i, {i, 2, Log[2, r]}, {n, 2, r^(1/i)}]]]]; lst2
CROSSREFS
Subsequence of A200878.
Sequence in context: A277723 A033018 A189781 * A358757 A353530 A244193
KEYWORD
base,nonn
AUTHOR
STATUS
approved

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Last modified June 13 05:35 EDT 2024. Contains 373366 sequences. (Running on oeis4.)