A297130 Numbers whose base-4 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}.

1, 2, 3, 5, 10, 15, 16, 20, 21, 22, 23, 26, 31, 32, 37, 40, 41, 42, 43, 47, 48, 53, 58, 60, 61, 62, 63, 64, 65, 66, 67, 69, 74, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 101, 104, 105, 106, 107, 111, 112, 117, 122, 124, 125, 126

Offset

1,2

Comments

These numbers comprise the complement of the set of numbers in the union of A297128 and A297129.

Links

Table of n, a(n) for n=1..63.

Example

Base-4 digits of 4997: 1,0,3,2,0,1,1, so that 4997 is in the sequence.

Mathematica

a[n_, b_] := Sign[Differences[IntegerDigits[n, b]]]; z = 300;
b = 4; t = Table[a[n, b], {n, 1, 10*z}];
u = Select[Range[z], ! MemberQ[t[[#]], 0] && First[t[[#]]] == 1 &]   (* A297128 *)
v = Select[Range[z], ! MemberQ[t[[#]], 0] && First[t[[#]]] == -1 &]  (* A297129 *)
Complement[Range[z], Union[u, v]]  (* A297130 *)

Crossrefs

Cf. A297128, A297129.

Sequence in context: A338589 A222406 A044953 * A044815 A048301 A043707

Adjacent sequences: A297127 A297128 A297129 * A297131 A297132 A297133

Keyword

nonn,easy,base

Author

Clark Kimberling, Jan 14 2018

Status

approved