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A044446
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Numbers k such that string 1,0 occurs in the base-4 representation of k but not of k+1.
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2
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4, 20, 36, 52, 84, 100, 116, 132, 148, 164, 180, 196, 212, 228, 244, 340, 356, 372, 388, 404, 420, 436, 452, 468, 484, 500, 516, 532, 548, 564, 596, 612, 628, 644, 660, 676, 692, 708, 724, 740, 756, 772, 788, 804, 820, 852, 868, 884, 900, 916, 932, 948, 964
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listen;
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OFFSET
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1,1
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LINKS
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PROG
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(Python)
from sympy.ntheory.factor_ import digits
def has10(k): s = "".join(map(str, digits(k, 4)[1:])); return "10" in s
def ok(n): return has10(n) and not has10(n+1)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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