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Search: id:A068146
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| A068146 |
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Primes of the form a^a - b^b. |
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+0
4
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| 3, 23, 229, 3121, 776887, 16774091, 275311670611, 302875106545597, 437893890380859119, 808793517812627212561, 827240252970236315921, 1978419655651397488675723, 20880467999847900922348207352551
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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The sum of the reciprocals converges to 0.3815001633628016571993127855719207322641604139242786445868829286575641435641531897479655590202266732... - Cino hilliard (hillcino368(AT)gmail.com), Dec 15 2002
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EXAMPLE
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229 = 4^4 - 3^3 is a prime.
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MATHEMATICA
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Select[ Union[ Flatten[ Table[a^a - b^b, {a, 1, 40}, {b, 1, a - 1} ]]], PrimeQ ]
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CROSSREFS
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Cf. A068145.
Sequence in context: A068955 A151393 A007781 this_sequence A162591 A122009 A151433
Adjacent sequences: A068143 A068144 A068145 this_sequence A068147 A068148 A068149
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KEYWORD
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easy,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Feb 23 2002
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EXTENSIONS
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Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com) and Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Mar 01 2002
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