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Search: id:A063792
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| A063792 |
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Subtractive primes: n = x1x2x3..xn = a prime in base 10 such that abs(x1-x2-x3-.....xn) is also a prime. |
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+0
4
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| 2, 3, 5, 7, 13, 29, 31, 41, 47, 53, 61, 79, 83, 97, 103, 113, 131, 139, 151, 157, 193, 199, 223, 227, 241, 263, 269, 281, 317, 337, 353, 359, 373, 379, 397, 401, 409, 433, 443, 461, 463, 487, 503, 521, 557, 571, 593, 599, 601, 613, 617, 631, 647, 653
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Harry J. Smith, Table of n, a(n) for n=1,...,1000
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EXAMPLE
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269 belong to the sequence because |2-6-9|=|-13|=13
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MATHEMATICA
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okQ[n_] := Module[{idn = -1# & /@ IntegerDigits[n]}, PrimeQ[Plus @@ Rest[idn] - First[idn]]]; Select[Prime[Range[120]], okQ]
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PROGRAM
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(PARI) SubD(x)= { local(s); s=0; while (x>9, s+=x-10*(x\10); x\=10); return(abs(s - x)) } { n=0; p=0; for (m=1, 10^9, p=nextprime(p+1); if(isprime(SubD(p)), write("b063792.txt", n++, " ", p); if (n==1000, break)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Aug 31 2009]
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CROSSREFS
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Sequence in context: A114741 A075238 A115261 this_sequence A167134 A071905 A067573
Adjacent sequences: A063789 A063790 A063791 this_sequence A063793 A063794 A063795
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KEYWORD
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easy,nonn,base
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AUTHOR
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Felice Russo (felice.russo(AT)katamail.com), Aug 17 2001
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EXTENSIONS
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Corrected by Harvey P. Dale (hpd1(AT)nyu.edu), Aug 20 2001
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