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A054217 Primes p with property that p concatenated with its emirp p' (prime reversal) forms a palindromic prime of the form 'primemirp' (rightmost digit of p and leftmost digit of p' are blended together - p and p' palindromic allowed). 5
2, 3, 5, 7, 13, 31, 37, 79, 113, 179, 181, 199, 353, 727, 787, 907, 937, 967, 983, 1153, 1193, 1201, 1409, 1583, 1597, 1657, 1831, 1879, 3083, 3089, 3319, 3343, 3391, 3541, 3643, 3853, 7057, 7177, 7507, 7681, 7867, 7949, 9103, 9127, 9173, 9209, 9439, 9547, 9601 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Original idea from G. L. Honaker, Jr..
LINKS
EXAMPLE
E.g., prime 113 has emirp 311 and 11311 is a palindromic prime, so 113 is a term.
MATHEMATICA
empQ[n_]:=Module[{idn=IntegerDigits[n], rev}, rev=Reverse[idn]; And@@PrimeQ[ {FromDigits[ rev], FromDigits[Join[Most[idn], rev]]}]]; Select[Prime[ Range[ 1200]], empQ] (* Harvey P. Dale, Mar 26 2013 *)
PROG
(Python)
from sympy import isprime
def ok(n):
if not isprime(n): return False
s = str(n); srev = s[::-1]
return isprime(int(srev)) and isprime(int(s[:-1] + srev))
print([k for k in range(10**4) if ok(k)]) # Michael S. Branicky, Nov 17 2023
CROSSREFS
Sequence in context: A359483 A067573 A103199 * A355521 A048414 A048399
KEYWORD
nonn,base,nice
AUTHOR
Patrick De Geest, Feb 15 2000
EXTENSIONS
Corrected (a(30)=3089 inserted) by Harvey P. Dale, Mar 26 2013
STATUS
approved

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Last modified May 19 14:45 EDT 2024. Contains 372698 sequences. (Running on oeis4.)