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A245356
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Number of numbers whose base-4/3 expansion (see A024631) has n digits.
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13
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4, 4, 4, 4, 8, 8, 12, 16, 20, 28, 36, 48, 64, 88, 116, 156, 208, 276, 368, 492, 656, 872, 1164, 1552, 2068, 2760, 3680, 4904, 6540, 8720, 11628, 15504, 20672, 27560, 36748, 48996, 65328, 87104, 116140, 154852, 206472, 275296, 367060, 489412, 652552, 870068
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OFFSET
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1,1
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LINKS
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FORMULA
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EXAMPLE
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a(3) = 4 because 320, 321, 322, and 323 are the base-4/3 expansions for the numbers 9, 10, 11, and 12 respectively and these are the only numbers with 3 digits.
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PROG
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(Sage)
A=[1]
for i in [1..60]:
A.append(ceil(((4-3)/3)*sum(A)))
[4*x for x in A]
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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