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 A306109 #5 Oct 12 2018 00:50:59
%S A306109 0,1,2,3,4,5,6,10,20,21,30,31,32,40,41,42,43,50,51,52,53,54,60,61,62,
%T A306109 63,64,65,101,102,103,104,105,106,201,202,203,204,205,206,212,213,214,
%U A306109 215,216,301,302,303,304,305,306,312,313,314,315,316,323,324,325,326,401,402,403,404,405,406,412,413,414,415
%N A306109 Numbers with digits in {0,...,6} such that every other digit is strictly less than its neighbors.
%C A306109 Terms of A032862 written in base 7.
%F A306109 a(n) = A007093(A032862(n)).
%o A306109 (PARI) A(Nmax=100, K=6, A=[0..K], i=vector(2*K, i, max(1, i-K+1)), c(T, v)=apply(t->t+T, v))={for(n=0, oo, for(k=10, K*11, if(k%10<k\10, k%10|| i=concat(i, 1+#A))&& A=concat(A, c(k*10^n, A[i[K*n+k%10+1]..i[K*n+K+1]-1])); #A<Nmax||return(A)))}
%Y A306109 Cf. A306105 .. A306111 and A297147: analog for bases 3..9 and 10.
%Y A306109 Cf. A032863 and A032858 .. A032865 for other bases 3..10.
%K A306109 nonn,base
%O A306109 1,3
%A A306109 _M. F. Hasler_, Oct 05 2018