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A164932

Prime numbers in which the sum of the largest digit and the smallest digit is also a prime.

11, 23, 29, 41, 43, 47, 61, 67, 83, 89, 103, 107, 163, 211, 223, 229, 233, 239, 241, 269, 293, 307, 383, 421, 431, 433, 443, 449, 457, 461, 467, 479, 499, 503, 523, 547, 587, 607, 613, 631, 641, 647, 661, 677, 683, 701, 829, 853, 857, 863, 883, 929, 947

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

If there is more than one digit with the same value (like in 211) only one is counted.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

The sum of the largest digit and the smallest digit in the prime 947 is also a prime.

MATHEMATICA

sldsdQ[n_]:=Module[{idn=IntegerDigits[n]}, PrimeQ[Min[idn]+Max[idn]]]; Select[Prime[Range[200]], sldsdQ] (* Harvey P. Dale, Jul 17 2018 *)

CROSSREFS