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 A088877 #18 Jun 08 2025 16:15:42
%S A088877 1,3,9,11,33,111,117,143,189,231,259,273,297,333,351,407,429,481,693,
%T A088877 777,819,1111,1233,1507,2409,3333,4521,7227,7373,11111,26829,27273,
%U A088877 33333,81819,100899,101101,108911,111111,123321,128713,129987,142857
%N A088877 Numbers k that are divisors of the number formed by concatenating (k-1), k and (k+1), in that order.
%C A088877 The sequence of numbers that divide the concatenation of k-1 and k+1 (A069871) is a subsequence of this sequence. - _David Wasserman_, Mar 26 2004
%H A088877 Paolo P. Lava, <a href="/A088877/b088877.txt">Table of n, a(n) for n = 1..100</a>
%e A088877 a(7)=117 because 117 is a divisor of 116117118.
%t A088877 Select[Range[143000],MemberQ[Divisors[FromDigits[Flatten[ IntegerDigits/@ {#-1,#,#+1}]]],#]&] (* _Harvey P. Dale_, Aug 27 2020 *)
%Y A088877 Cf. A069871.
%K A088877 base,nonn
%O A088877 1,2
%A A088877 _Chuck Seggelin_, Oct 20 2003