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Search: id:A053098
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| A053098 |
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When the Euler phi function is iterated with initial value A002110(n)=primorial, a(n)= first (maximal) power of 2 emerging during iteration. |
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+0
1
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| 2, 2, 8, 16, 128, 512, 8192, 16384, 262144, 2097152, 16777216, 67108864, 2147483648, 8589934592, 274877906944, 4398046511104, 70368744177664, 1125899906842624, 18014398509481984, 288230376151711744
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OFFSET
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1,1
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COMMENT
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Analogous to A053047 (the same with a similar large initial value, n!)
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EXAMPLE
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n=6, A002110(6)=30030; the corresponding iteration chain is: {30030,5760,1536,512,256,128,64,32,16,8,4,2,1}. The first power of 2 is the 4-th item after 3 iterations.It is 512, therefore a(6)=512.
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CROSSREFS
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A000010, A002110.
Sequence in context: A016120 A085542 A009725 this_sequence A067640 A098277 A080040
Adjacent sequences: A053095 A053096 A053097 this_sequence A053099 A053100 A053101
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Feb 28 2000
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