This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A180006 #17 Jan 26 2025 16:35:16
%S A180006 91,32,92,14,34,74,35,95,16,76,38,98,301,901,721,731,931,361,371,391,
%T A180006 791,112,322,722,922,332,932,142,152,752,362,962,172,772,182,382,392,
%U A180006 703,713,133,943,763,973,793,104,904,914,124,134,334,934,344,944,754
%N A180006 Composite numbers that can be obtained from primes by interchanging the first and last digits.
%C A180006 The primes must contain at least two digits.
%H A180006 Harvey P. Dale, <a href="/A180006/b180006.txt">Table of n, a(n) for n = 1..1000</a>
%e A180006 The composite number 752 is obtained from the prime 257 by interchanging the first and last digits.
%t A180006 Select[With[{idn=IntegerDigits[#]},FromDigits[Join[{idn[[-1]]},Most[Rest[idn]],{idn[[1]]}]]]&/@Prime[Range[5,1500]],CompositeQ] (* _Harvey P. Dale_, Jan 26 2025 *)
%Y A180006 The corresponding primes are A076056. Cf. A002808, A179826.
%K A180006 nonn,base
%O A180006 1,1
%A A180006 _Parthasarathy Nambi_, Aug 06 2010
%E A180006 More terms from _Vincenzo Librandi_, Aug 06 2010