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 A216063 #33 Aug 15 2025 03:50:14 %S A216063 126,133,63,32,26,27,42,33,1,16,15,11,76,15,26,19,18,8,1,45,38,19,12, %T A216063 16,30,22,11,21,1,16,16,11,12,11,13,10,23,10,1,22,19,6,18,25,23,11,10, %U A216063 6,1,6,8,20,14,17,11,13,14,13,1,15,14,17,21,16,16,9,4,11 %N A216063 a(n) is the conjectured highest power of n which has no two identical digits in succession. %C A216063 Contribution from _Charles R Greathouse IV_, Sep 17 2012: (Start) %C A216063 a(n) = 0 for infinitely many n; such n have positive density in this sequence. Question: are such n of density 1? %C A216063 A naive heuristic suggests that there are infinitely many n such that a(n) = 6 but only finitely many a(n) such that a(n) > 6. This suggests a weaker conjecture: this sequence is bounded. (End) %H A216063 T. D. Noe, <a href="/A216063/b216063.txt">Table of n, a(n) for n = 2..1000</a> (terms 2 to 99 from V. Raman). %e A216063 3^133 = 2865014852390475710679572105323242035759805416923029389510561523 which has no two adjacent identical digits. %t A216063 Table[mx = 0; Do[If[! MemberQ[Differences[IntegerDigits[n^k]], 0], mx = k], {k, 1000}]; mx, {n, 2, 100}] (* _T. D. Noe_, Sep 17 2012 *) %o A216063 (PARI) isA043096(n)=my(v=digits(n));for(i=2,#v,if(v[i]==v[i-1],return(0)));1 %o A216063 a(n)=my(best=0); if(n==14,76,for(k=1, max(9,94\sqrt(log(n))), if(isA043096(n^k), best=k)); best ) \\ (conjectural) _Charles R Greathouse IV_, Sep 17 2012 %Y A216063 Cf. A043096, A216064, A216065, A215236. %K A216063 nonn,base %O A216063 2,1 %A A216063 _V. Raman_, Sep 01 2012