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.
%I A015942 #16 Mar 25 2021 12:39:31 %S A015942 6,18,42,54,126,162,294,342,378,486,882,1026,1134,1314,1458,1806,2058, %T A015942 2394,2646,3078,3402,3942,4374,5334,5418,6174,6498,7182,7938,9198, %U A015942 9234,10206,11826,12642,13122,14154,14406,16002,16254,16758 %N A015942 Positive integers n such that n | (2^n + n/2 - 1). %F A015942 a(n) = 2 * A014945(n). [_Max Alekseyev_, Aug 04 2011] %o A015942 (Python) %o A015942 A015942_list = [n for n in range(2,10**6,2) if pow(2,n,n) == n//2+1] # _Chai Wah Wu_, Mar 25 2021 %Y A015942 Cf. A015945. %K A015942 nonn,easy %O A015942 1,1 %A A015942 _Robert G. Wilson v_