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Search: id:A136341
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| A136341 |
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Fibonacci primes or semiprimes F(k) such that F(k+1) is again prime or semiprime. |
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1
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OFFSET
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1,1
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FORMULA
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Let F(n) = n-th Fibonacci number and define a 2-almost prime number to be a number with only 2 prime divisors with multiplicity.
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EXAMPLE
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(55,89) is an almost twin Fibonacci prime pair because 55=5*11 is a 2-almost prime and 89 is prime.
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PROGRAM
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(PARI) ATfib(n) = for(x=3, n, f1=fibonacci(x); f2=fibonacci(x+1); if(bigomega (f1)<=2&&bigomega(f2)<=2, print1(f1", ")))
(PARI) for( k=3, 10^5, bigomega( fibonacci( k++ ))>2 & next; bigomega( fibonacci( k-1 ))>2 & next; print1(fibonacci(k--)", ")) \\ - M. F. Hasler, May 01 2008
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CROSSREFS
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Cf. A001358.
Adjacent sequences: A136338 A136339 A136340 this_sequence A136342 A136343 A136344
Sequence in context: A135118 A084958 A037392 this_sequence A139563 A019226 A138699
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KEYWORD
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more,nonn
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AUTHOR
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Cino Hilliard (hillcino368(AT)hotmail.com), Mar 28 2008
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EXTENSIONS
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Edited by M. F. Hasler (Maximilian.Hasler(AT)gmail.com), May 01 2008
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