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A030144
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Primes in which parity of digits alternates.
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18
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2, 3, 5, 7, 23, 29, 41, 43, 47, 61, 67, 83, 89, 101, 103, 107, 109, 127, 149, 163, 167, 181, 307, 347, 349, 367, 383, 389, 503, 509, 521, 523, 541, 547, 563, 569, 587, 701, 709, 727, 743, 761, 769, 787, 907, 929, 941, 947, 967, 983, 2129, 2141, 2143, 2161, 2309
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OFFSET
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1,1
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LINKS
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FORMULA
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EXAMPLE
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2129 is a term as 2, 1, 2 and 9 have even and odd parity alternately.
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MATHEMATICA
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Join[{2, 3, 5, 7}, Select[Prime[Range[400]], Union[Abs[Differences[Boole/@ EvenQ[ IntegerDigits[#]]]]] == {1}&]] (* Harvey P. Dale, Jul 26 2011 *)
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PROG
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(Haskell)
a030144 n = a030144_list !! (n-1)
a030144_list = filter ((== 1) . a228710) a000040_list
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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