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A054518
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Emirpnons (nonprimes whose reversal is a different nonprime).
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1
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10, 12, 15, 18, 21, 24, 25, 26, 27, 28, 36, 39, 40, 42, 45, 46, 48, 49, 51, 52, 54, 56, 57, 58, 60, 62, 63, 64, 65, 68, 69, 72, 75, 78, 80, 81, 82, 84, 85, 86, 87, 90, 93, 94, 96, 100, 102, 105, 108, 114, 115, 116, 117, 120
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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LINKS
| Harvey P. Dale, Table of n, a(n) for n = 0..1000
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EXAMPLE
| a(1)=12 because 12 is not a prime, neither is 21 and 12<>21
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MATHEMATICA
| emirpnonQ[n_]:=Module[{idn=IntegerDigits[n], ridn}, ridn=Reverse[idn]; n>9&&ridn!=idn&&!PrimeQ[FromDigits[ridn]]]; With[{nprs=Complement[ Range[ 120], Prime[ Range[PrimePi[120]]]]}, Select[nprs, emirpnonQ]] (* From Harvey P. Dale, Feb 05 2012 *)
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CROSSREFS
| Cf. A006567.
Sequence in context: A161990 A030591 A006793 * A072198 A057485 A162825
Adjacent sequences: A054515 A054516 A054517 * A054519 A054520 A054521
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KEYWORD
| base,easy,nonn,changed
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AUTHOR
| Henry Bottomley (se16(AT)btinternet.com), Apr 07 2000
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