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A061365 Numbers k such that either k or its reversal (but not both) is prime. 1
14, 16, 19, 20, 23, 29, 30, 32, 34, 35, 38, 41, 43, 47, 50, 53, 59, 61, 67, 70, 74, 76, 83, 89, 91, 92, 95, 98, 103, 104, 106, 109, 110, 112, 118, 119, 124, 125, 127, 128, 130, 133, 134, 136, 137, 139, 140, 142, 145, 146, 152, 160, 163, 164, 166 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1000

EXAMPLE

14=2*7 is a term as 41 is prime but 14 is not;

13 is not a term as its reversal is also a prime.

MATHEMATICA

Select[ Range[169], Xor[ PrimeQ[ # ], PrimeQ[ FromDigits[ Reverse[ IntegerDigits[ # ]]]]] & ]

PROG

(PARI) { n=0; for (m=0, 3910, x=m; r=0; while (x>0, d=x-10*(x\10); x\=10; r=r*10 + d); if ((isprime(m) + isprime(r)) == 1, write("b061365.txt", n++, " ", m)) ) } \\ Harry J. Smith, Jul 21 2009

CROSSREFS

Sequence in context: A177982 A034305 A091898 * A327822 A102107 A217707

Adjacent sequences:  A061362 A061363 A061364 * A061366 A061367 A061368

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, May 21 2002

STATUS

approved

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Last modified September 21 13:20 EDT 2020. Contains 337272 sequences. (Running on oeis4.)