# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a208155 Showing 1-1 of 1 %I A208155 #23 Mar 28 2019 13:13:34 %S A208155 15,49,91,133,217,259,301,427,469,511,553,679,721,763,889,973,1015, %T A208155 1057,1099,1141,1267,1351,1393,1477,1561,1603,1687,1897,1939,1981, %U A208155 2107,2149,2191,2317,2359,2443,2569,2611,2653,2779,2863,2947,3031,3073,3199,3241,3409 %N A208155 7-Knödel numbers. %H A208155 Amiram Eldar, Table of n, a(n) for n = 1..10000 %H A208155 Eric Weisstein, Knödel Numbers. %p A208155 with(numtheory); %p A208155 knodel:= proc(i,k) %p A208155 local a,n,ok; %p A208155 for n from k+1 to i do %p A208155 ok:=1; %p A208155 for a from 1 to n do %p A208155 if gcd(a,n)=1 then if (a^(n-k) mod n)<>1 then ok:=0; break; fi; fi; %p A208155 od; %p A208155 if ok=1 then print(n); fi; %p A208155 od; %p A208155 end: %p A208155 knodel(10000,7); %t A208155 (* First run program for A208154 to define knodelQ *) Select[Range[3500], knodelQ[#, 7] &] (* _Alonso del Arte_, Feb 24 2012 *) %Y A208155 Cf. A002997, A050990, A033553, A050992, A050993, A208154, A208156-A208158. %K A208155 nonn %O A208155 1,1 %A A208155 _Paolo P. Lava_, Feb 24 2012 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE