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 A072872 #14 Mar 15 2020 02:17:48
%S A072872 1,2,4,4,3,4,11,8,5,14,7,4,10,16,16,16,30,16,30,16,11,58,75,16,34,10,
%T A072872 5,16,6,16,8,32,58,30,16,16,58,30,10,16,33,16,54,92,16,118,224,16,36,
%U A072872 34,59,16,36,34,63,16,130,6,64,16,43,8,16,64,16,58,210,84,118,16,43,16,32
%N A072872 a(n) is the smallest positive number k such that n divides 2^k - k.
%C A072872 If n is a power of 2, a(n) = n. Conjecture : if n > 47, a(n) < prime(n).
%H A072872 Harvey P. Dale, <a href="/A072872/b072872.txt">Table of n, a(n) for n = 1..1000</a>
%t A072872 dvkn[n_]:=Module[{k=1},While[!Divisible[2^k-k,n],k++];k]; Array[dvkn,80] (* _Harvey P. Dale_, Dec 23 2011 *)
%o A072872 (PARI) a(n) = for(k=1, oo, if(Mod(2, n)^k==k, return(k))); \\ _Jinyuan Wang_, Mar 15 2020
%Y A072872 See A135359 for another version.
%Y A072872 Cf. A247248.
%K A072872 nonn,easy
%O A072872 1,2
%A A072872 _Benoit Cloitre_, Jul 28 2002
%E A072872 Edited by _N. J. A. Sloane_, May 27 2010