A077752 Smallest number whose cube begins and ends in n, or 0 if no such number exists.

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

Robert Israel, Table of n, a(n) for n = 0..10000

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

Adjacent sequences: A077749 A077750 A077751 * A077753 A077754 A077755

Keyword

base,nonn,look

Author

Amarnath Murthy, Nov 20 2002

Extensions

More terms from Sascha Kurz, Jan 07 2003

Status

approved