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Search: id:A092250
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| A092250 |
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Lesser of the greatest twin prime pair with n digits. |
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+0
1
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| 5, 71, 881, 9929, 99989, 999959, 9999971, 99999587, 999999191, 9999999701, 99999999761, 999999999959, 9999999998489, 99999999999971, 999999999997967, 9999999999999641, 99999999999998807, 999999999999998927
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Sum of reciprocals = .215331408..
Also the numerator of the largest prime over prime fraction less than 10^n. - Cino Hilliard (hillcino368(AT)gmail.com), Feb 13 2006
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PROGRAM
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(PARI) lasttwpr(n) = { sr=0; for(m=0, n, c=0; forstep(x=10^(m+1)-1, 10^m, -2, if(isprime(x)&& isprime(x-2), print1(x-2", "); sr+=1./(x-2); break) ) ); print(); print(sr) }
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CROSSREFS
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Sequence in context: A123077 A064752 A033507 this_sequence A133990 A120808 A092204
Adjacent sequences: A092247 A092248 A092249 this_sequence A092251 A092252 A092253
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KEYWORD
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base,nonn
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AUTHOR
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Cino Hilliard (hillcino368(AT)gmail.com), Feb 17 2004
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