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A320930
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Numbers k such that 4^k starts with k.
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7
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OFFSET
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1,1
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LINKS
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EXAMPLE
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4^10 = 1048576 starts with 10, so 10 is in the sequence.
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MAPLE
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filter:= proc(n) local t, b;
t:= 4^n;
b:= ilog10(t) - ilog10(n);
floor(t/10^b) = n
end proc:
select(filter, [$1..10^5]);
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PROG
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(Python)
def afind(limit, startk=1):
k, pow4 = startk, 4**startk
for k in range(startk, limit+1):
if str(pow4).startswith(str(k)):
print(k, end=", ")
pow4 *= 4
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CROSSREFS
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KEYWORD
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nonn,base,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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