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A077337
Numbers k such that k and R(k) both are squarefree where R(n) (A004086) is the digit reversal of n.
2
1, 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 22, 26, 30, 31, 33, 34, 35, 37, 38, 39, 41, 43, 47, 51, 53, 55, 58, 59, 62, 66, 70, 71, 73, 74, 77, 78, 79, 83, 85, 87, 91, 93, 95, 97, 101, 102, 103, 105, 106, 107, 109, 110, 111, 113, 114, 115, 118, 119, 122, 123, 127, 129
OFFSET
1,2
LINKS
Cécile Dartyge, Bruno Martin, Joël Rivat, Igor E. Shparlinski, and Cathy Swaenepoel, Reversible primes, arXiv:2309.11380 [math.NT], 2023. See p. 6.
MATHEMATICA
Select[Range[200], And@@SquareFreeQ/@{#, FromDigits[Reverse[ IntegerDigits[ #]]]}&] (* Harvey P. Dale, Jan 04 2014 *)
Select[Range[200], AllTrue[{#, IntegerReverse[#]}, SquareFreeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 16 2018 *)
CROSSREFS
Sequence in context: A326537 A302798 A294472 * A093501 A087007 A047586
KEYWORD
base,easy,nonn,less
AUTHOR
Amarnath Murthy, Nov 04 2002
EXTENSIONS
More terms from David Wasserman, Oct 25 2006
STATUS
approved