

A115261


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.


4



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
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OFFSET

1,1


LINKS

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000


EXAMPLE

1237 is in the sequence because it is prime and abs((7+2)(3+1)) = 5 is prime


MAPLE

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:


CROSSREFS

Cf. A040997, A005017, A063792, A087593, A042939, A041000, A040164, A115259, A115260.
Sequence in context: A075238 A346408 A158281 * A063792 A270391 A172508
Adjacent sequences: A115258 A115259 A115260 * A115262 A115263 A115264


KEYWORD

base,nonn


AUTHOR

Paolo P. Lava and Giorgio Balzarotti, Jan 20 2006


STATUS

approved



