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A114236
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n(k) is the minimum number of n that makes 2*Prime[k]+Prime[k-n] a prime.
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3
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1, 1, 1, 1, 1, 5, 3, 4, 4, 2, 2, 1, 1, 2, 6, 1, 2, 8, 5, 2, 2, 2, 1, 4, 1, 1, 5, 11, 1, 1, 2, 2, 8, 3, 2, 5, 2, 2, 3, 1, 1, 1, 1, 5, 2, 3, 1, 10, 4, 4, 4, 1, 5, 12, 9, 1, 2, 1, 5, 3, 1, 1, 1, 1, 12, 2, 1, 6, 6, 5, 1, 5, 3, 8, 3, 6, 4, 4, 6, 5, 1, 1, 4, 2, 5, 11, 4, 11, 6, 12, 1, 6, 1, 3, 7, 10, 1, 9, 5, 3, 3, 9
(list; graph; refs; listen; history; internal format)
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OFFSET
| 3,6
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EXAMPLE
| k=3: 2*Prime[3]+Prime[3-1]=2*5+3=13 is prime, so n(3)=1;
k=4: 2*Prime[4]+Prime[4-1]=2*7+5=19 is prime, so n(4)=1;
...
k=8: 2*Prime[8]+Prime[8-5]=2*19+5=43 is prime, so n(8)=5;
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MATHEMATICA
| Table[p1 = Prime[n1]; n2 = 1; p2 = Prime[n1 - n2]; While[cp = 2*p1 + p2; ! PrimeQ[cp], n2++; If[n2 >= n1, Print[n1]]; p2 = Prime[n1 - n2]]; n2, {n1, 3, 202}]
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CROSSREFS
| Cf. A114227, A114230, A073703, A114228, A114231, A114233, A114235.
Sequence in context: A135448 A168360 A107488 * A178481 A171545 A137898
Adjacent sequences: A114233 A114234 A114235 * A114237 A114238 A114239
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KEYWORD
| easy,nonn
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AUTHOR
| Lei Zhou (lzhou5(AT)emory.edu), Nov 20 2005
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