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A077752
Smallest number whose cube begins and ends in n, or 0 if no such number exists.
2
0, 1, 28, 7, 74, 175, 86, 43, 2, 99, 0, 2271, 108, 517, 0, 0, 256, 2573, 0, 1239, 0, 12841, 0, 2847, 624, 1365, 0, 3, 1412, 309, 0, 6811, 318, 6977, 0, 0, 1546, 3333, 0, 1579, 0, 7481, 0, 3507, 164, 0, 0, 363, 7872, 17049, 0, 17251, 8078, 8137, 0, 0, 1786, 1793, 0
OFFSET
0,3
LINKS
MAPLE
f:= proc(n) local S, Sa, k, m, x, a;
m:= 1 + ilog10(n);
S:= map(t -> subs(t, x), [msolve(x^3=n, 10^m)]);
if S = [] then return 0 fi;
for k from 0 do
a:= ceil((n*10^k)^(1/3));
Sa:= map(s -> (s-a) mod 10^m, S);
x:= a + min(Sa);
if x^3 < (n+1)*10^k then return x fi;
od
end proc:
f(0):= 0:
map(f, [$0..100]); # Robert Israel, Nov 19 2019
CROSSREFS
a(n) = A077751(n)^(1/3).
Sequence in context: A040766 A040764 A040763 * A300563 A040762 A040761
KEYWORD
base,nonn,look
AUTHOR
Amarnath Murthy, Nov 20 2002
EXTENSIONS
More terms from Sascha Kurz, Jan 07 2003
STATUS
approved