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Search: id:A007377
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| A007377 |
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Numbers n such that decimal expansion of 2^n contains no 0.
(Formerly M0485)
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+0
27
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| 1, 2, 3, 4, 5, 6, 7, 8, 9, 13, 14, 15, 16, 18, 19, 24, 25, 27, 28, 31, 32, 33, 34, 35, 36, 37, 39, 49, 51, 67, 72, 76, 77, 81, 86
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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It is an open problem of long standing to show that 86 is the last term.
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REFERENCES
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J. S. Madachy, Mathematics on Vacation, Scribner's, NY, 1966, p. 126.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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W. Schneider, NoZeros: Powers n^k without Digit Zero
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
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MATHEMATICA
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Do[ If[ Union[ RealDigits[ 2^n ] [[1]]] [[1]] != 0, Print[ n ] ], {n, 1, 60000}]
Select[Range@1000, First@Union@IntegerDigits[2^# ] != 0 &]
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CROSSREFS
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Cf. A102483.
Sequence in context: A094823 A032973 A092598 this_sequence A135140 A052061 A045540
Adjacent sequences: A007374 A007375 A007376 this_sequence A007378 A007379 A007380
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KEYWORD
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fini,nonn,base
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com), Robert G. Wilson v (rgwv(AT)rgwv.com)
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