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A180743
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Ascending sequence of numbers such that the sum of any two distinct elements (even + odd) is a prime number.
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1
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1, 2, 3, 4, 9, 10, 27, 57, 69, 70, 267, 429, 1059, 1227, 1479, 2547, 2787, 3249, 3459, 3537, 4089, 4719, 5097, 6267, 6357, 6567, 6957, 8997, 9039, 10089, 12039, 12819, 13719, 16689, 16977, 17289, 17919, 18909, 19377, 19419, 19749
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OFFSET
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1,2
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LINKS
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EXAMPLE
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70 + 69 = 139 is prime ;
70 + 57 = 127 is prime ;
70 + 9 = 79 is prime ;
70 + 3 = 73 is prime ;
70 + 1 = 71 is prime.
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MAPLE
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with(numtheory):nn:=50: T:=array(1..nn): T[1]:=1:T[2]:=2:a:=2:a0:=1:a1:=1:for
k from 3 to nn do:id:=0:for n from k to 20000 while(id=0) do:n1:=irem(n, 2):i:=0:for
p from 1 to a do: if n=T[p] then i:=0:else fi: x:=n+T[p]:if type(x, prime)=true
then i:=i+1:else fi:od: if (i=a1 and n1=0) or (i=a0 and n1=1) then T[k]:=n:a0:=a0+irem(n1+1, 2):a1:=a1+n1:printf(`%d, `, n):a:=a+1:id:=1: else fi:od:od:
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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