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Search: id:A082125
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| A082125 |
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Smallest difference>1 between d and p/d for any divisor d of the partial product p of the sequence, starting with 4. |
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+0
6
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| 4, 3, 4, 2, 4, 8, 16, 64, 512, 16384, 2097152, 2147483648, 140737488355328, 1180591620717411303424, 40564819207303340847894502572032, 365375409332725729550921208179070754913983135744
(list; graph; listen)
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OFFSET
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0,1
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COMMENT
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a(n) is a power of two for n>1 and log_2(a(n))=A073941(n) for n>2. - Ralf Stephan, Apr 16 20.
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LINKS
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R. Stephan, [math/0305348] On a sequence related to the Josephus problem
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PROGRAM
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(PARI) p=4:for(n=1, 50, v=divisors(p):r=sqrt(p):t=0:for(k=1, matsize(v)[2], if(v[k]>=r, t=k:break)): if(v[t]^2==p, u=t, u=t-1): if(v[t]-v[u]<2, u=u-1:t=t+1):print1(v[t]-v[u]", "):p=p*(v[t]-v[u]))
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CROSSREFS
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Cf. A082120, A003681 (starts with 2, 3), A082126.
Cf. A029744.
Sequence in context: A066340 A143505 A161882 this_sequence A058290 A002285 A106049
Adjacent sequences: A082122 A082123 A082124 this_sequence A082126 A082127 A082128
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KEYWORD
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nonn,hard
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AUTHOR
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Ralf Stephan (ralf(AT)ark.in-berlin.de), Apr 04 2003
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