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A084487
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Prime(n)+q, where q is the next prime such that q mod 4 = prime(n) mod 4.
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2
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10, 18, 18, 30, 30, 46, 42, 54, 66, 74, 78, 94, 90, 106, 114, 126, 134, 138, 150, 162, 162, 186, 186, 198, 210, 210, 234, 222, 250, 258, 270, 286, 290, 306, 314, 330, 330, 346, 354, 370, 374, 390, 390, 426, 410, 434, 450, 466, 462, 474, 490, 498, 514, 526, 534
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OFFSET
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2,1
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LINKS
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EXAMPLE
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Prime(5) = 11, 11 mod 4 = 3, 13 mod 4 = 1, 17 mod 4 = 1, 19 mod 4 = 3, hence a(5) = 11+19 = 30.
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MATHEMATICA
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nq4[n_]:=Module[{q=NextPrime[n], m=Mod[n, 4]}, While[Mod[q, 4]!=m, q= NextPrime[ q]]; n+q]; Table[nq4[n], {n, Prime[Range[2, 60]]}] (* Harvey P. Dale, Aug 18 2019 *)
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PROG
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(PARI) {forprime(p=3, 270, m=p%4; q=nextprime(p+1); while(q%4!=m, q=nextprime(q+1)); print1(p+q, ", "))}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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