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A084924
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Let t(x) be the highest power of 2 which divides x+1. Then a(1)=3; a(n) is the least prime p for which t(p) > t(a(n-1)).
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1
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3, 7, 31, 127, 1279, 3583, 5119, 6143, 8191, 81919, 131071, 524287, 14680063, 109051903, 654311423, 738197503, 2147483647, 21474836479, 51539607551, 824633720831, 13743895347199, 26388279066623, 246290604621823
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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LINKS
| M. F. Hasler, Table of n, a(n) for n = 1..100
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EXAMPLE
| a(5)=1279 because t(a(4))=7 and 1279 is the least prime with t(p)>7.
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PROG
| (PARI) a=vector(50); a[1]=3; for(i=2, length(a), j=k=2^(factor(a[i-1]+1, 2)[1, 2]+1); while(! isprime(j-1), j+=k); a[i]=j-1); a - M. F. Hasler (maximilian.hasler(AT)gmail.com), Mar 15 2007
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CROSSREFS
| Sequence in context: A145038 A138864 A105768 * A001348 A006515 A093535
Adjacent sequences: A084921 A084922 A084923 * A084925 A084926 A084927
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KEYWORD
| nonn
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AUTHOR
| Shane Findley (TTcreation(AT)aol.com), Jul 15 2003
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EXTENSIONS
| Edited by Don Reble (djr(AT)nk.ca), May 08 2004
More terms from M. F. Hasler (maximilian.hasler(AT)gmail.com), Mar 15 2007
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