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A069490
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Primes > 1000 in which every substring of lengths 2 and 3 are also prime.
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4
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1373, 3137, 3797, 6131, 6173, 6197, 9719, 11311, 11317, 17971, 31379, 61379, 71971, 113131, 113173, 113797, 131311, 131317, 131797, 179719, 317971, 431311, 431797, 617971, 1131131, 1131379, 1311311, 1313797, 1317971, 3131137, 3131311
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| 11317 is a term as the substrings of length 2 i.e. 11,13,31,17 and the three substrings of length 3 i.e. 113,131 and 317 are all prime.
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MATHEMATICA
| Do[ If[ Union[ PrimeQ[ Map[ FromDigits, Partition[ IntegerDigits[ Prime[n]], 2, 1]]]] == Union[ PrimeQ[ Map[ FromDigits, Partition[ IntegerDigits[ Prime[n]], 3, 1]]]] == {True}, Print[ Prime[n]]], {n, PrimePi[1000] + 1, 10^5}]
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CROSSREFS
| Cf. A069488 and A069489.
Sequence in context: A140125 A179915 A168167 * A045131 A056049 A206340
Adjacent sequences: A069487 A069488 A069489 * A069491 A069492 A069493
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KEYWORD
| nonn
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AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 30 2002
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EXTENSIONS
| Edited, corrected and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Apr 12 2002
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