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 A286289 #25 Nov 12 2019 15:09:53
%S A286289 314,6,315,14,1
%N A286289 Least number to start a run of exactly n nondecreasing values of the Euler phi function (A000010).
%C A286289 a(6) > 10^7. - _Michael De Vlieger_, May 19 2017
%C A286289 a(6) > 10^13. - _Giovanni Resta_, Nov 12 2019
%D A286289 M. F. Hasler, Posting to Sequence Fans Mailing List, May 06 2017
%e A286289 From _Michael De Vlieger_, May 19 2017: (Start)
%e A286289 A run of subsequent numbers with nondecreasing phi is of length 1 if it consists of a single number n with phi(n-1) > phi(n) > phi(n+1) (else n belongs to a run of length >= 2). This happens first for a(1) = 314.
%e A286289 Phi(14..18) = (6, 8, 8, 16, 6), therefore the first run of 4 numbers with nondecreasing phi(= A000010) starts at a(4) = 14. (End)
%t A286289 Prepend[#, Module[{k = 2}, While[Sign@ Differences@ EulerPhi[k + {-1, 0, 1}] != {-1, -1}, k++];k]] &@ Function[s, Function[r, If[Length@ # > 0, #[[1, 1]], -1] &@ Select[s, Length@ # == r &]] /@ Range@ Max@ Map[Length, s]]@ DeleteCases[SplitBy[MapIndexed[Function[k, (2 Boole[#1 <= #2] - 1) k & @@ #1]@ First@ #2 &, Partition[Array[EulerPhi, 10^7], 2, 1]], Sign], w_ /; First@ w < 0] (* _Michael De Vlieger_, May 19 2017 *)
%Y A286289 Cf. A000010, A284597, A285893, A286287, A286288.
%K A286289 nonn,more
%O A286289 1,1
%A A286289 _N. J. A. Sloane_, May 16 2017