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Search: id:A112714
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| A112714 |
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Numbers of the form k*2^m-1 with k<2^m and k odd. |
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+0
4
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| 1, 3, 7, 11, 15, 23, 31, 39, 47, 55, 63, 79, 95, 111, 127, 143, 159, 175, 191, 207, 223, 239, 255, 287, 319, 351, 383, 415, 447, 479, 511, 543, 575, 607, 639, 671, 703, 735, 767, 799, 831, 863, 895, 927, 959, 991, 1023, 1087, 1151, 1215, 1279, 1343, 1407
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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Eric Weisstein's World of Mathematics, Proth Numbers
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EXAMPLE
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a(4)=7 because 7=1*2^3-1, with 1<2^3 and it is the fourth number of this form.
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MATHEMATICA
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Take[Sort@Flatten@Table[k*2^m - 1, {m, 0, 10}, {k, 1, 2^m - 1, 2}], 53] (from Robert G. Wilson v (rgwv(at)rgwv.com), Jan 02 2006)
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PROGRAM
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(PARI) for(n=2, 8, for(k=2^(n-2)+1, 2^n, print1(k*2^n-1", "))) Note that the first two terms ( 1, 3 ) are not computed
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CROSSREFS
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Cf. A080075.
Sequence in context: A160785 A095100 A036994 this_sequence A160808 A151567 A139250
Adjacent sequences: A112711 A112712 A112713 this_sequence A112715 A112716 A112717
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KEYWORD
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easy,nonn
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AUTHOR
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Jose Brox (tautocrona(AT)terra.es), Dec 31 2005
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