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 A171551 #4 Oct 19 2021 21:18:53
%S A171551 0,1,2,3,4,7,8,9,10,12,13,15,18,20,21,22,23,24,26,27,29,37,50
%N A171551 Numbers n with property that decimal expansion of 3^n-2^n contains no pair of neighbor equal digits (probably finite).
%e A171551 50 is a term because 3^50-2^50 = 717897986565952681927625,
%e A171551 while 49 is not because 3^49-2^49 = 2392(99)328(66)7(66)7576168(77)1 (four pairs of neighbor equal digits).
%t A171551 Reap[Do[id=IntegerDigits[3^m-2^m];rm=Rest[id]-Most[id];If[FreeQ[rm,0],Sow[m]],{m,0,10000}]][[2,1]]
%Y A171551 Cf. A050723 (2^n), A050724 (3^n), A171550 (3^n+2^n).
%K A171551 base,fini,full,nonn
%O A171551 0,3
%A A171551 _Zak Seidov_, Dec 11 2009