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Search: id:A079352
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| A079352 |
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a(1)=1, then a(n)=3*a(n-1) if n is already in the sequence, a(n)=2*a(n-1) otherwise. |
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+0
2
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| 1, 2, 4, 12, 24, 48, 96, 192, 384, 768, 1536, 4608, 9216, 18432, 36864, 73728, 147456, 294912, 589824, 1179648, 2359296, 4718592, 9437184, 28311552, 56623104, 113246208, 226492416, 452984832, 905969664, 1811939328, 3623878656
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Inspired by A079000. Cf. A064437.
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FORMULA
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a(n+1)=3*a(n) for n=3 n of the form 3*2^k - 1, k>=2 . a(n+1)=2*a(n) otherwise. Hence a(n)=3*(3/2)^floor((log(n/3))/log(2))*2^n.
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PROGRAM
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(PARI) a(n)=3*(3/2)^floor((log(n)-log(3))/log(2))*2^n
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CROSSREFS
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Sequence in context: A163908 A108720 A089822 this_sequence A089888 A133411 A004645
Adjacent sequences: A079349 A079350 A079351 this_sequence A079353 A079354 A079355
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KEYWORD
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nonn
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AUTHOR
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Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 14 2003
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