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 A069706 Primes with property that swapping first and last digits also gives a prime. 5
 2, 3, 5, 7, 11, 13, 17, 31, 37, 71, 73, 79, 97, 101, 107, 113, 131, 149, 151, 157, 167, 179, 181, 191, 199, 311, 313, 337, 347, 353, 359, 373, 383, 389, 701, 709, 727, 733, 739, 743, 751, 757, 761, 769, 787, 797, 907, 919, 929, 937, 941, 953, 967, 971, 983, 991, 1009, 1013 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This is not the same as A007500, "palindromic" primes. LINKS Chai Wah Wu, Table of n, a(n) for n = 1..10000 EXAMPLE 1049 and 9041 both are primes hence both are members. MAPLE swapdigs:= proc(n) local d;   d:= ilog10(n);   n + ((n mod 10)-floor(n/10^d))*(10^d-1); end proc: select(isprime and isprime @ swapdigs, [2, seq(2*i+1, i=1..10^4)]); # Robert Israel, Nov 11 2015 MATHEMATICA Do[t = IntegerDigits[ Prime[n]]; u = t; u[[1]] = t[[ -1]]; u[[ -1]] = t[[1]]; t = FromDigits[u]; If[ PrimeQ[t], Print[ Prime[n]]], {n, 1, 300}] PROG (Python) from sympy import prime, isprime A069706_list = [2, 3, 5, 7] for i in range(5, 10**6):     p = prime(i)     s = str(p)     if isprime(int(s[-1]+s[1:-1]+s[0])):         A069706_list.append(p) # Chai Wah Wu, Nov 11 2015 CROSSREFS Cf. A007500, A069707, A069708. Sequence in context: A211655 A055387 A061461 * A007500 A090933 A107845 Adjacent sequences:  A069703 A069704 A069705 * A069707 A069708 A069709 KEYWORD nonn,base AUTHOR Amarnath Murthy, Apr 08 2002 EXTENSIONS Edited and extended by Robert G. Wilson v, Apr 12 2002 Edited by N. J. A. Sloane, Jan 20 2009 STATUS approved

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Last modified February 24 04:36 EST 2020. Contains 332197 sequences. (Running on oeis4.)