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A245877
Primes p such that p - d and p + d are also primes, where d is the largest digit of p.
2
263, 563, 613, 653, 1613, 1663, 3463, 4643, 5563, 5653, 6263, 6323, 12653, 13463, 14633, 16063, 16223, 21163, 21563, 25463, 26113, 30643, 32063, 33623, 36313, 41263, 41603, 44263, 53623, 54623, 56003, 60133, 61553, 62213, 62633, 64013, 65413, 105613, 106213
OFFSET
1,1
COMMENTS
Intersection of A245742 and A245743.
The largest digit of a(n) is 6, and the least significant digit of a(n) is 3.
Intersection of A006489, A011536, and complements of A011537, A011538, A011539. - Robert Israel, Aug 05 2014
LINKS
EXAMPLE
The prime 263 is in the sequence because 263 - 6 = 257 and 263 + 6 = 269 are both primes.
MATHEMATICA
pdpQ[n_]:=Module[{m=Max[IntegerDigits[n]]}, AllTrue[n+{m, -m}, PrimeQ]]; Select[ Prime[Range[11000]], pdpQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jan 13 2017 *)
PROG
(PARI) select(p->d=vecsort(digits(p), , 4)[1]; isprime(p-d) && isprime(p+d), primes(20000))
(Python)
import sympy
from sympy import prime
from sympy import isprime
for n in range(1, 10**5):
..s=prime(n)
..lst = []
..for i in str(s):
....lst.append(int(i))
..if isprime(s+max(lst)) and isprime(s-max(lst)):
....print(s, end=', ')
# Derek Orr, Aug 13 2014
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Colin Barker, Aug 05 2014
STATUS
approved