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 A108107 Numbers n such that the string 1123n is the decimal expansion of a prime number. 0
 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; text; internal format)
 OFFSET 1,1 COMMENTS 11 and 23 are primes. LINKS 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. 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) PROG (MAGMA) [ n: n in [1..700] | IsPrime(Seqint(Intseq(n) cat [3, 2, 1, 1])) ]; CROSSREFS Cf. A107645, A107644. Sequence in context: A022701 A276003 A255343 * A216168 A036303 A116455 Adjacent sequences:  A108104 A108105 A108106 * A108108 A108109 A108110 KEYWORD nonn,base AUTHOR Parthasarathy Nambi, Jun 25 2005 EXTENSIONS More terms from Emeric Deutsch, Jul 02 2005 STATUS approved

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Last modified June 25 09:48 EDT 2019. Contains 324347 sequences. (Running on oeis4.)