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Search: id:A135772
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| A135772 |
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Numbers having equal number of divisors and binary digits. |
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+0
9
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| 1, 2, 3, 4, 8, 10, 14, 15, 16, 32, 44, 45, 50, 52, 63, 64, 128, 130, 135, 136, 138, 152, 154, 165, 170, 174, 182, 184, 186, 189, 190, 195, 222, 230, 231, 232, 238, 246, 248, 250, 255, 256, 441, 484, 512, 567, 592, 656, 688, 752, 848, 891, 944, 976
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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a(1) = 1 since 1 has 1 divisor and 1 binary digit.
a(2),a(3) = 2,3 since 2=10[2] and 3=11[2] have 2 divisors and 2 binary digits.
a(4) = 4 = 100[2] is the only number with 3 binary digits having 3 divisors.
8,10,14,15 have 4 binary digits and 4 divisors.
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PROGRAM
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(PARI) for(d=1, 10, for(n=2^(d-1), 2^d-1, d==numdiv(n)&print1(n", ")))
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CROSSREFS
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Cf. A135773-A135779, A095862.
Adjacent sequences: A135769 A135770 A135771 this_sequence A135773 A135774 A135775
Sequence in context: A073465 A121612 A061193 this_sequence A051783 A033083 A005542
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KEYWORD
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base,nonn
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AUTHOR
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M. F. Hasler (Maximilian.Hasler(AT)gmail.com), Nov 28 2007
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