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A141747
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a(n) is the number of nonnegative integer pairs i,j such that n = 2^i + 3^j.
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2
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0, 1, 1, 1, 2, 0, 1, 0, 1, 1, 2, 0, 1, 0, 0, 0, 2, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 2, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0
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OFFSET
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1,5
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LINKS
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FORMULA
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G.f.: ( Sum_{i>=0} x^(2^i) ) * ( Sum_{j>=0} x^(3^j) ). - Ilya Gutkovskiy, Feb 10 2022
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EXAMPLE
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a(5) = 2, using (i,j) = (1,1) and (2,0).
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MAPLE
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f:= proc(n) local j, t, s;
t:= 0;
for j from 0 to floor(log[3](n)) do
s:= n - 3^j;
if s = 2^padic:-ordp(s, 2) then t:= t+1 fi
od;
t
end proc:
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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