cp's OEIS Frontend

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.

A263108 Semiprimes m such that the leftward cyclic permutation of its decimal digits is a larger semiprime.

This page as a plain text file.
%I A263108 #21 Jul 21 2018 03:20:25
%S A263108 15,26,39,49,58,122,129,134,141,145,155,158,159,161,177,178,183,185,
%T A263108 187,226,254,262,298,339,341,355,358,362,371,381,391,393,394,445,451,
%U A263108 469,473,493,497,565,581,583,586,589,674,781,791,889,895,899,1114,1119
%N A263108 Semiprimes m such that the leftward cyclic permutation of its decimal digits is a larger semiprime.
%C A263108 Subsequence of A263106.
%H A263108 Zak Seidov, <a href="/A263108/b263108.txt">Table of n, a(n) for n = 1..28070</a> (all terms up to 10^6)
%e A263108 Permute the digits of 15 = 3 * 5 to get 51 = 3 * 17.
%e A263108 Permute the digits of 26 = 2 * 13 to get 62 = 2 * 31.
%e A263108 Permute the digits of 122 = 2 * 61 to get 221 = 13 * 17.
%e A263108 Permute the digits of 129 = 3 * 43 to get 291 = 3 * 97.
%t A263108 Select[Range[4, 1000000], 2 == PrimeOmega[#] == PrimeOmega[fd = FromDigits[RotateLeft[IntegerDigits[#]]]] && fd > # &] (* for b-file *)
%Y A263108 Cf. A001292, A001358, A085751, A263106.
%K A263108 nonn,base
%O A263108 1,1
%A A263108 _Zak Seidov_, Oct 09 2015