# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a276970 Showing 1-1 of 1 %I A276970 #15 Oct 15 2018 11:44:18 %S A276970 1,3,5,9,17,21,27,45,63,99,105,117,153,171,189,207,261,273,279,333, %T A276970 369,387,423,429,477,513,531,549,585,603,639,657,711,747,801,873,909, %U A276970 927,945,963,981,1017,1143,1179,1197,1209,1233,1251,1341,1359,1365,1413,1467,1503,1557,1611,1629,1665,1719,1737 %N A276970 Odd integers n such that 2^n == 2^9 (mod n). %C A276970 Also, integers n such that 2^(n-9) == 1 (mod n). %C A276970 Contains A208157 as a subsequence. %C A276970 For all m, 2^A128123(m)-1 belongs to this sequence. %H A276970 Seiichi Manyama, <a href="/A276970/b276970.txt">Table of n, a(n) for n = 1..10000</a> %t A276970 m = 2^9; Join[Select[Range[1, m, 2], Divisible[2^# - m, #] &], Select[Range[m + 1, 10^3, 2], PowerMod[2, #, #] == m &]] (* _Robert Price_, Oct 15 2018 *) %Y A276970 The odd terms of A015931. %Y A276970 Odd integers n such that 2^n == 2^k (mod n): A176997 (k=1), A173572 (k=2), A276967 (k=3), A033984 (k=4), A276968 (k=5), A215610 (k=6), A276969 (k=7), A215611 (k=8), this sequence (k=9), A215612 (k=10), A276971 (k=11), A215613 (k=12). %K A276970 nonn,easy %O A276970 1,2 %A A276970 _Max Alekseyev_, Sep 22 2016 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE