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A249837
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a(n+1) is the next smallest nontrivial cube beginning with a(n), initial term is 9.
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1
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9, 9261, 92615351886784, 9261535188678457128255779014690172977343833, 926153518867845712825577901469017297734383369607525414854584903918819898290730346512973206455943454340951813592133138664220381927
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OFFSET
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1,1
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COMMENTS
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LINKS
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MAPLE
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nextterm:= proc(x) local d, s, t;
for d from 1 do
s:= traperror(ceil((x*10^d+1)^(1/3)));
while not type(s, integer) do
Digits:= Digits *2;
s:= traperror(ceil((x*10^d+1)^(1/3)));
od:
t:= traperror(floor(((x+1)*10^d-1)^(1/3)));
while not type(t, integer) do
Digits:= Digits *2;
t:= traperror(floor(((x+1)*10^d-1)^(1/3)));
od:
if s <= t then return s^3 fi;
od:
end proc:
a[1]:= 9;
for n from 2 to 6 do a[n]:= nextterm(a[n-1]) od; # Robert Israel, Dec 04 2014
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PROG
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(Python)
def f(x):
..n = x
..s = 1
..while s < 10**7:
....if s % 10:
......S = str(s**3)
......if S.startswith(str(n)):
........print(s**3, end=', ')
........n = s**3
....s += 1
f(9)
(PARI) a(n)=k=n; s=1; while(s<10^7, if(s%10, if(s^3\(10^(#Str(s^3)-#Str(k)))==k, print1(s^3, ", "); k=s^3)); s++)
a(9)
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CROSSREFS
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KEYWORD
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nonn,more,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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