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A108107
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Numbers n such that the string 1123n is the decimal expansion of a prime number.
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0
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9, 27, 31, 37, 39, 49, 61, 63, 97, 127, 151, 181, 189, 211, 217, 219, 231, 247, 267, 279, 303, 307, 319, 327, 349, 351, 361, 379, 391, 399, 403, 427, 429, 439, 477, 483, 487, 501, 511, 517, 531, 541, 553, 561, 567, 589, 597, 601, 621, 631, 637, 651, 667
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| 11 and 23 are primes.
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EXAMPLE
| 9 is in the sequence because 11239 is prime.
63 is in the sequence because 112363 is prime.
127 is in the sequence because 1123127 is prime.
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MAPLE
| a:=proc(n) local z: z:=nops(convert(n, base, 10)): if isprime(1123*10^z+n)=true then n else fi end: seq(a(n), n=1..750); (Deutsch)
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PROG
| (MAGMA) [ n: n in [1..700] | IsPrime(Seqint(Intseq(n) cat [3, 2, 1, 1])) ];
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CROSSREFS
| Cf. A107645, A107644.
Sequence in context: A122985 A115148 A022701 * A036303 A116455 A103753
Adjacent sequences: A108104 A108105 A108106 * A108108 A108109 A108110
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KEYWORD
| nonn,base
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AUTHOR
| Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Jun 25 2005
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EXTENSIONS
| More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Jul 02 2005
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