A117060 Mersenne numbers for which the product of the digits is not zero.

1, 3, 7, 15, 31, 63, 127, 255, 511, 8191, 16383, 32767, 65535, 262143, 524287, 16777215, 33554431, 134217727, 268435455, 2147483647, 4294967295, 8589934591, 17179869183, 34359738367, 68719476735, 137438953471, 549755813887, 562949953421311

Offset

1,2

Comments

These are all the Mersenne numbers for which no digit is 0. The indices of these numbers are A007377.

Links

Arkadiusz Wesolowski, Table of n, a(n) for n = 1..35

Formula

a(n) = 2^(A007377(n)) - 1. [Arkadiusz Wesolowski, Jun 28 2011]

Mathematica

Flatten[Table[If[First@Union@IntegerDigits[2^n - 1] != 0, 2^n - 1, {}], {n, 100}]] (* Arkadiusz Wesolowski, Sep 04 2011 *)

Prog

(Perl) use bignum;
for(1..99) {
  if((1<<$_) =~ /^[1-9]+$/) {
    print(((1 << $_) - 1) . ", ")
  }
} # Charles R Greathouse IV, Jun 30 2011
(PARI) for(n=1, 99, if(vecmin(eval(Vec(Str(2^n)))), print1(2^n-1", "))) \\ Charles R Greathouse IV, Jun 30 2011

Crossrefs

Cf. A000225, A007377.

Sequence in context: A000225 A168604 A123121 * A178460 A351755 A057613

Adjacent sequences: A117057 A117058 A117059 * A117061 A117062 A117063

Keyword

base,nonn

Author

Luc Stevens (lms022(AT)yahoo.com), Apr 16 2006

Extensions

Offset corrected by Arkadiusz Wesolowski, Jun 28 2011

Corrected by Arkadiusz Wesolowski, Oct 03 2011

Status

approved