A077751 Smallest cube that begins and ends in n, or 0 if no such cube exists.

0, 1, 21952, 343, 405224, 5359375, 636056, 79507, 8, 970299, 0, 11712548511, 1259712, 138188413, 0, 0, 16777216, 17034106517, 0, 1902014919, 0, 2117368939321, 0, 23076099423, 242970624, 2543302125, 0, 27, 2815166528, 29503629, 0, 315960389731, 32157432

Offset

0,3

Links

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

Maple

f:= proc(n) local m, d, x, R, Rn, n1, n2, n0;
      m:= 1+ilog10(n);
      R:= map(t -> rhs(op(t)), {msolve(x^3=n, 10^m)});
      if R = {} then return 0 fi;
      for d from 0 do
        n1:= ceil(surd(n*10^d, 3));
        n2:= ceil(surd((n+1)*10^d, 3))-1;
        Rn:= (R -~ n1) mod 10^m;
        n0:= min(Rn) + n1;
        if n0 <= n2 then return n0^3 fi
      od
end proc:
f(0):= 0:
map(f, [$0..50]); # Robert Israel, Apr 16 2026

Crossrefs

Cf. A000578, A077752.

Sequence in context: A031647 A045109 A206126 * A066693 A262821 A250569

Adjacent sequences: A077748 A077749 A077750 * A077752 A077753 A077754

Keyword

nonn,look,base

Author

Amarnath Murthy, Nov 20 2002

Extensions

More terms from Sascha Kurz, Jan 07 2003

Corrected and extended by Franklin T. Adams-Watters, Jul 19 2006

Status

approved