%I #11 Aug 13 2024 11:14:57
%S 1,4,7,9,15,16,18,22,24,28,31,34,37,39,42,43,46,49,51,52,55,60,63,66,
%T 72,78,79,81,85,87,90,93,94,108,112,114,115,129,133,138,141,154,157,
%U 159,162,163,169,171,177,178,180,181,184,192,195,196,204,205,211,222
%N Numbers k such that k prefixed by '9' and followed by '1' is prime.
%Y Cf. A032702-A032733.
%K nonn,base
%O 1,2
%A _Patrick De Geest_, May 15 1998
%E Offset changed by _Andrew Howroyd_, Aug 13 2024