A263108 - 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