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
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