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A045049 Numbers whose base-4 representation contains exactly two 0's and two 2's. 1
130, 136, 160, 266, 290, 296, 386, 392, 416, 518, 521, 523, 526, 530, 536, 545, 547, 548, 556, 562, 568, 578, 584, 608, 641, 643, 644, 652, 656, 688, 706, 712, 736, 778, 802, 808, 898, 904, 928, 1050, 1062, 1065, 1067, 1070 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Enrique Pérez Herrero, Table of n, a(n) for n = 1..100000
MATHEMATICA
fQ[n_] := Block[{idn = IntegerDigits[n, 4]}, Count[idn, 0] == Count[idn, 2] == 2]; Select[Range@1100, fQ] (* Robert G. Wilson v, Dec 11 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") == 2):
print(a)
# Enrique Pérez Herrero, Dec 06 2017
CROSSREFS
Cf. A007090.
Sequence in context: A043604 A250740 A025372 * A163555 A025373 A025364
KEYWORD
nonn,base
AUTHOR
STATUS
approved

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Last modified May 26 05:37 EDT 2024. Contains 372807 sequences. (Running on oeis4.)