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A078706
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a(n) = smallest integer >=a(n-1) such that sum of first n terms is prime.
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2
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2, 3, 6, 6, 6, 6, 8, 10, 12, 12, 12, 14, 16, 18, 18, 18, 24, 32, 34, 36, 38, 42, 46, 48, 54, 56, 64, 68, 78, 90, 90, 94, 102, 114, 122, 124, 134, 144, 148, 150, 152, 160, 168, 170, 178, 182, 190, 192, 200, 216, 220, 222, 234, 234, 234, 246, 260, 264, 268, 270, 278, 280
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OFFSET
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1,1
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LINKS
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EXAMPLE
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a(1)=2, the first prime. The smallest integer >=2 that yields a prime when added to 2 is 3, so a(2)=3. The smallest integer >=3 that yields a prime when added to 2+3 is 6 so a(3)=6.
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MATHEMATICA
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s = 0; NestList[(s += #; NextPrime[s + # - 1] - s) &, 2, 61] (* Ivan Neretin, May 14 2015 *)
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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