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A120226
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Numbers n such that a+n and a*n+1 are prime, case a=4.
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3
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1, 3, 7, 9, 13, 15, 25, 27, 37, 39, 43, 49, 57, 67, 69, 79, 93, 97, 99, 105, 127, 135, 153, 163, 169, 175, 177, 189, 193, 207, 219, 235, 253, 265, 267, 273, 277, 279, 303, 307, 309, 343, 345, 363, 405, 417, 427, 435, 475, 483, 487, 499, 517, 553, 559, 567, 573
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Prime numbers p such that 4+p and 4*p+1 are prime A106057. Case a=5 A120227.
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MATHEMATICA
| Reap[Do[Do[If[PrimeQ[{n+x, n*x+1}]=={True, True}, Sow[x]], {x, 1, 1000, 2}], {n, 4, 4}]][[2, 1]]
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CROSSREFS
| Cf. A092945, A106057 A085063, A120223, A120224, A120225, A120227.
Sequence in context: A024901 A000959 A204085 * A137310 A118567 A118561
Adjacent sequences: A120223 A120224 A120225 * A120227 A120228 A120229
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KEYWORD
| nonn
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AUTHOR
| Zak Seidov (zakseidov(AT)yahoo.com), Jun 10 2006
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