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A159270
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Number of positive integers m<=n such that 2^m+3^n or 2^n+3^m is prime.
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2
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0, 1, 2, 2, 3, 3, 3, 4, 5, 3, 5, 3, 6, 6, 4, 4, 7, 6, 8, 4, 4, 4, 4, 6, 7, 2, 4, 5, 6, 6, 8, 6, 10, 3, 3, 5, 6, 4, 9, 6, 9, 7, 5, 5, 9, 6, 8, 7, 7, 10, 4, 5, 8, 9, 1, 8, 6, 6, 7, 7, 10, 5, 5, 4, 10, 8, 7, 8, 8, 2, 3, 8, 8, 8, 5, 6, 7, 5, 10, 6, 7, 7, 8, 10, 10, 9, 10, 5, 7, 5, 5, 6, 9, 6, 5, 5, 12, 3, 7, 6, 8, 9
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OFFSET
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0,3
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COMMENTS
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Zeros occur at n = 0 and for n in A159625.
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LINKS
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David Broadhurst, 2^m+3^n and 2^n+3^m, Prime numbers and primality testing Group, Apr 11 2009. [Broken link]
Maximilian Hasler, Mike Oakes, Mark Underwood, David Broadhurst and others, Primes of the form (x+1)^p-x^p, digest of 22 messages in primenumbers Yahoo group, Apr 5 - May 7, 2009. [Cached copy]
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PROG
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(PARI) A159270(n)=sum(m=1, n, ispseudoprime(2^n+3^m) || ispseudoprime(3^n+2^m))
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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