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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); # Emeric Deutsch, Jul 02 2005
PROG
(Magma) [ n: n in [1..700] | IsPrime(Seqint(Intseq(n) cat [3, 2, 1, 1])) ];
CROSSREFS
Sequence in context: A022701 A276003 A255343 * A340237 A216168 A036303
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 March 19 03:33 EDT 2024. Contains 370952 sequences. (Running on oeis4.)