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 A101446 #17 Jun 04 2025 11:10:22
%S A101446 2,1,1,1,1,1,3,1,1,1,1,10,1,5,1,1,2,2,1,1,1,2,4,1,4,1,12,1,328,1,1,6,
%T A101446 24,77,1,8,75,1,1,2,1,2,13,1,1,1,14,1,3,1,45,3,1,1,1,1,8,625,1,1,22,3,
%U A101446 3,1,1,1,11,1,4,1,2,33803,5,10,64,1,3,8,2,5,2,2
%N A101446 a(n)= least k such that n^k*(n^k-1)-1 is prime with n > 1.
%C A101446 a(73) > 2475. - _Ray Chandler_, Jan 27 2005
%H A101446 Michael S. Branicky, <a href="/A101446/b101446.txt">Table of n, a(n) for n = 2..147</a>
%e A101446 2^2*(2^2-1)-1=11 prime so a(2)=2.
%t A101446 f[n_] := Block[{k = 1, c}, While[c = n^k; ! PrimeQ[c*(c - 1) - 1], k++ ]; Return[k]; ]; Table[f[n], {n, 2, 72}] (* _Ray Chandler_, Jan 27 2005 *)
%o A101446 (PARI) a(n) = {my(k=1); while (!ispseudoprime(n^k*(n^k-1)-1), k++); k;} \\ _Michel Marcus_, Sep 16 2019
%Y A101446 Cf. A101406.
%K A101446 nonn
%O A101446 2,1
%A A101446 _Pierre CAMI_, Jan 24 2005
%E A101446 a(55)-a(72) from _Ray Chandler_, Jan 27 2005
%E A101446 a(73) and beyond from _Michael S. Branicky_, Jun 04 2025