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Search: id:A138148
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| A138148 |
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Cyclops numbers with binary digits only. |
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+0
8
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| 0, 101, 11011, 1110111, 111101111, 11111011111, 1111110111111, 111111101111111, 11111111011111111, 1111111110111111111, 111111111101111111111, 11111111111011111111111
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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All members are palindromes A002113. First five members are mentioned in A129868.
Also, binary representation of A129868.
a(A090748(n)) is equal to A138831(n), the n-th perfect number minus 1, written in base 2.
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EXAMPLE
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n ........ a(n) ... A129868(n)
0 ......... 0 ......... 0
1 ........ 101 ........ 5
2 ....... 11011 ....... 27
3 ...... 1110111 ...... 119
4 ..... 111101111 ..... 495
5 .... 11111011111 .... 2015
6 ... 1111110111111 ... 8127
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CROSSREFS
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Cyclops numbers: A134808. Cf. A002113, A129868.
Cf. A000396, A090748, A135627, A138831.
Sequence in context: A100027 A097727 A083981 this_sequence A138831 A068160 A156669
Adjacent sequences: A138145 A138146 A138147 this_sequence A138149 A138150 A138151
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KEYWORD
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easy,nonn,base
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AUTHOR
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Omar E. Pol (info(AT)polprimos.com), Mar 18 2008m Apr 08 2008
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