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A129747
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Numbers n such that the sum of the first n primes with the final digit 7 is prime.
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1
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1, 3, 7, 9, 11, 17, 31, 43, 63, 77, 81, 101, 109, 111, 117, 123, 127, 137, 147, 149, 153, 157, 161, 167, 171, 193, 199, 231, 233, 241, 243, 281, 311, 317, 321, 327, 329, 347, 367, 393, 421, 433, 439, 443, 483, 499, 531, 587, 591, 611, 619, 621, 623, 679, 683
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OFFSET
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1,2
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LINKS
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FORMULA
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MATHEMATICA
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Position[Accumulate[Select[Prime[Range[3000]], Mod[#, 10]==7&]], _?(PrimeQ[ #]&)]//Flatten (* Harvey P. Dale, Dec 27 2021 *)
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CROSSREFS
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KEYWORD
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easy,base,less,nonn
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AUTHOR
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STATUS
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approved
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