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Search: id:A114267
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| A114267 |
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n(k) is the minimum number that require at least k to make 2*Prime[n]+Prime[n+k] a prime. |
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+0
1
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| 1, 11, 4, 12, 19, 13, 34, 31, 36, 42, 62, 59, 142, 158, 247, 173, 240, 273, 204, 417, 231, 669, 172, 348, 965, 1003, 115, 1369, 370, 1244, 1251, 1373, 983, 1109, 2489, 1028, 2583, 1506, 6506, 6773, 7762, 5525, 2463, 6534, 6451, 3587, 4944, 3119, 3178, 4880
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OFFSET
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1,2
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EXAMPLE
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2*Prime[1]+Prime[1+1]=2*2+3=7 is prime, so n(1)=1;
2*Prime[2]+Prime[2+1]=2*3+5=11 is prime, not count
...
2*Prime[4]+Prime[4+1]=2*7+11=25 is not prime
2*Prime[4]+Prime[4+2]=2*7+13=27 is not prime
2*Prime[4]+Prime[4+3]=2*7+17=31 is prime, so n[3]=4;
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MATHEMATICA
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Do[n[k] = 0, {k, 1, 2000}]; ct = 0; nm = 0; n2 = 0; n1 = 1; p1 = 2; While[ct < 200, n2 = 1; p2 = Prime[n1 + n2]; While[cp = 2*p1 + p2; ! PrimeQ[cp], n2++; p2 = Prime[n1 + n2]]; If[n[n2] == 0, n[ n2] = n1; If[n2 > nm, nm = n2]; If[n2 ≤ 200, ct++ ]; Print[Table[n[k], {k, 1, nm}]]]; n1++; p1 = Prime[n1]]
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CROSSREFS
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Cf. A114227, A114230, A073703, A114235, A114262, A114265, A114229, A114232, A114234, A114237, A114264, A114266.
Sequence in context: A110782 A088073 A010187 this_sequence A141240 A038318 A010186
Adjacent sequences: A114264 A114265 A114266 this_sequence A114268 A114269 A114270
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KEYWORD
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nonn
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AUTHOR
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Lei Zhou (lzhou5(AT)emory.edu), Nov 20 2005
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