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 A289285 #9 Jul 24 2017 12:53:40
%S A289285 1,6,11,61,62,5,2,51,63,4,3,41,64,31,65,21,66,12,52,53,42,54,32,55,22,
%T A289285 56,13,43,44,33,45,23,46,14,34,35,24,36,15,25,26,16,17
%N A289285 Starting with a(1) = 1, a(n) = smallest nonnegative integer not yet in the sequence such that the last digit of a(n-1) plus the first digit of a(n) is equal to 7. The digit 0 is not allowed.
%C A289285 The number of terms of this finite sequence is the seventh central polygonal number, n = 43.
%t A289285 Module[{a = {1}, k, d = 7}, TimeConstrained[Do[k = 2; While[Or[MemberQ[a, k], MemberQ[IntegerDigits@ k, 0], # != d] &[Mod[a[[n - 1]], 10] + First@ IntegerDigits@ k], k++]; AppendTo[a, k], {n, 2, 100}], 2]; a] (* _Michael De Vlieger_, Jul 14 2017 *)
%Y A289285 Cf. A002061, A289283, A289284.
%K A289285 nonn,base,fini,full
%O A289285 1,2
%A A289285 _Enrique Navarrete_, Jul 01 2017