Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #21 Jul 21 2018 03:20:25
%S 15,26,39,49,58,122,129,134,141,145,155,158,159,161,177,178,183,185,
%T 187,226,254,262,298,339,341,355,358,362,371,381,391,393,394,445,451,
%U 469,473,493,497,565,581,583,586,589,674,781,791,889,895,899,1114,1119
%N Semiprimes m such that the leftward cyclic permutation of its decimal digits is a larger semiprime.
%C Subsequence of A263106.
%H Zak Seidov, <a href="/A263108/b263108.txt">Table of n, a(n) for n = 1..28070</a> (all terms up to 10^6)
%e Permute the digits of 15 = 3 * 5 to get 51 = 3 * 17.
%e Permute the digits of 26 = 2 * 13 to get 62 = 2 * 31.
%e Permute the digits of 122 = 2 * 61 to get 221 = 13 * 17.
%e Permute the digits of 129 = 3 * 43 to get 291 = 3 * 97.
%t Select[Range[4, 1000000], 2 == PrimeOmega[#] == PrimeOmega[fd = FromDigits[RotateLeft[IntegerDigits[#]]]] && fd > # &] (* for b-file *)
%Y Cf. A001292, A001358, A085751, A263106.
%K nonn,base
%O 1,1
%A _Zak Seidov_, Oct 09 2015