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A089396
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Smallest n-digit term of A089395.
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2
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OFFSET
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0,2
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LINKS
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EXAMPLE
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a(3) = 256 which is the smallest 3-digit number such that 2*56 + 1 = 113, 25*6 + 1 = 151 and 256 + 1 = 257 are all prime.
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MAPLE
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with(combinat): ds:=proc(s) local j: RETURN(add(s[j]*10^(j-1), j=1..nops(s))):end: for d from 1 to 7 do sch:=[seq([1, op(i), d+1], i=[[], seq([j], j=2..d)])]: for n from 10^(d-1) to 10^d-1 do sn:=convert(n, base, 10): fl:=0: for s in sch do m:=mul(j, j=[seq(ds(sn[s[i]..s[i+1]-1]), i=1..nops(s)-1)])+1: if not isprime(m) then fl:=1: break fi od: if fl=0 then printf("%d, ", n):break fi od od: # C. Ronaldo
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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Corrected and extended by C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 25 2004
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STATUS
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approved
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