A045051 Numbers whose base-4 representation contains exactly two 0's and four 2's.

2090, 2186, 2210, 2216, 2570, 2594, 2600, 2690, 2696, 2720, 4266, 4650, 4746, 4770, 4776, 6186, 6282, 6306, 6312, 6666, 6690, 6696, 6786, 6792, 6816, 8298, 8346, 8358, 8361, 8363, 8366, 8378, 8426, 8490, 8586, 8610

Offset

1,1

Links

Enrique Pérez Herrero, Table of n, a(n) for n = 1..60000

Mathematica

Select[Range[4^4, 4^7], {#4, #2} == {2, 4} & @@ DigitCount[#, 4] &] (* Michael De Vlieger, Dec 03 2017 *)

Prog

(Python)
import numpy as np
for a in range(10000):
    x = np.base_repr(a, base=4)
    if(x.count("0") == 2 and x.count("2") == 4):
        print(a)
# Enrique Pérez Herrero, Dec 03 2017

Crossrefs

Cf. A007090.

Sequence in context: A179124 A206606 A089159 * A102504 A270761 A332643

Adjacent sequences: A045048 A045049 A045050 * A045052 A045053 A045054

Keyword

nonn,base

Author

Clark Kimberling

Status

approved