Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #4 Jan 14 2018 23:01:54
%S 1,2,3,4,6,12,18,24,25,30,31,32,33,34,37,43,49,50,56,60,61,62,63,64,
%T 68,74,75,81,87,90,91,92,93,94,99,100,106,112,118,120,121,122,123,124,
%U 125,126,127,128,129,131,137,143,149,150,151,152,153,154,155,156
%N Numbers whose base-5 digits d(m), d(m-1),..., d(0) have m=0 or else d(i) = d(i+1) for some i in {0,1,...,m-1}.
%C These numbers comprise the complement of the set of numbers in the union of A297131 and A297132.
%e Base-5 digits of 5000: 1,3,0,0,0,0, so that 5000is in the sequence.
%t a[n_, b_] := Sign[Differences[IntegerDigits[n, b]]]; z = 300;
%t b = 5; t = Table[a[n, b], {n, 1, 10*z}];
%t u = Select[Range[z], ! MemberQ[t[[#]], 0] && First[t[[#]]] == 1 &] (* A297131 *)
%t v = Select[Range[z], ! MemberQ[t[[#]], 0] && First[t[[#]]] == -1 &] (* A297132 *)
%t Complement[Range[z], Union[u, v]] (* A297133 *)
%Y Cf. A297131, A297132.
%K nonn,easy,base
%O 1,2
%A _Clark Kimberling_, Jan 14 2018