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A087594
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Define dd(n) = the number formed by concatenating the absolute difference of successive digits. Sequence contains primes p such that dd(p)=q is a prime, dd(q) is also a prime = r and so on until a single-digit prime (2,3,5,7) arises. (Primes in which the number formed by successive digit differences are primes at every step until a single-digit prime is obtained.).
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4
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13, 29, 31, 41, 47, 53, 61, 79, 83, 97, 103, 113, 163, 227, 229, 331, 347, 367, 401, 449, 487, 503, 521, 523, 541, 547, 557, 563, 569, 587, 601, 661, 709, 743, 769, 821, 823, 881, 883, 907, 941, 947, 967, 997, 1063, 1069, 1103, 1163, 1481, 1609, 1621, 1663
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OFFSET
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0,1
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COMMENTS
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Conjecture: Sequence is infinite. Subsidiary sequence: number of n-digit members.
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LINKS
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Harvey P. Dale, Table of n, a(n) for n = 0..1000
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EXAMPLE
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29 is a member as absolute(2-9) = 7 is a prime.
347 is a member as dd(347) = 13, dd(13) = 2.
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MATHEMATICA
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adsd[n_]:=FromDigits[Abs/@Differences[IntegerDigits[n]]]; Select[Prime[ Range[ 300]], And@@PrimeQ[NestWhileList[adsd, adsd[#], IntegerLength[#]>1&]]&] (* Harvey P. Dale, Mar 16 2013 *)
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CROSSREFS
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Cf. A087593, A087595.
Sequence in context: A293661 A087593 A158075 * A320868 A347816 A319167
Adjacent sequences: A087591 A087592 A087593 * A087595 A087596 A087597
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KEYWORD
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base,nonn
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AUTHOR
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Amarnath Murthy, Sep 18 2003
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EXTENSIONS
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More terms from David Wasserman, Jun 15 2005
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STATUS
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approved
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