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Search: id:A115261
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| A115261 |
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Prime numbers such that the absolute difference of the sum of their digits in odd positions and the sum of their digits in even positions is also a prime. |
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+0
3
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| 2, 3, 5, 7, 13, 29, 31, 41, 47, 53, 61, 79, 83, 97, 101, 113, 137, 139, 151, 157, 163, 167, 173, 179, 191, 193, 211, 223, 227, 233, 251, 269, 277, 281, 283, 311, 313, 337, 359, 379, 383, 401, 409, 421, 431, 443, 467, 487, 541, 557, 563, 577, 599, 601, 607, 641
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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1237 is in the sequence because it is prime and abs((7+2)-(3+1)) = 5 is prime
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MAPLE
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Df:=proc(N) j:=1; for n from 1 while j<=N do B:= convert(ithprime(n), base, 10); ap:=-(sum(B[2*i], i=1..nops(B)/2)-sum(B[2*n+1], i=0..(nops(B)-1)/2)); if (isprime(abs(ap)) = true) then a[j]:=ithprime(n); j:=j+1; fi; od; end:
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CROSSREFS
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Cf. A040997, A005017, A063792, A087593, A042939, A041000, A040164, A115259, A115260.
Sequence in context: A037021 A114741 A075238 this_sequence A063792 A103600 A071905
Adjacent sequences: A115258 A115259 A115260 this_sequence A115262 A115263 A115264
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KEYWORD
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base,nonn
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AUTHOR
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Paolo P. Lava and Giorgio Balzarotti (greenblue(AT)tiscali.it), Jan 20 2006
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