A074112 Let omega(m) be the number of distinct prime divisors of m. Then a(n) is the largest n-digit squarefree number such that omega(n) > omega(j) for all j < n.

6, 78, 966, 9870, 99330, 930930, 9699690, 99953490, 999068070, 9592993410, 99978788910, 999890501610, 9814524629910, 99999887777790, 998448347106210, 9999999768941490, 99992911041433410, 997799870344687410, 9999839051940347610, 99987077573596883670

Offset

1,1

Links

Charlie Neder, Table of n, a(n) for n = 1..33

Charlie Neder, Python program for computing this sequence

Maple

A074112 := proc(n)
    option remember;
    local a, o, wrks, j ;
    if n = 1 then
        return 6;
    end if;
    for a from 10^n-1 to 10^(n-2) by -1 do
        if numtheory[issqrfree](a) then
            o := omega(a) ;
            wrks := true;
            for j from 1 to n-1 do
                if omega(procname(j)) >= o then
                    wrks := false;
                    break;
                end if;
            end do:
            if wrks then
                return a;
            end if;
        end if;
    end do:
    return -1 ;
end proc:
for j from 1 do
    print( A074112(j)) ;
end do: # R. J. Mathar, Oct 03 2014

Crossrefs

Cf. A002110, A074111.

Sequence in context: A068884 A186663 A069670 * A372181 A197103 A345360

Adjacent sequences: A074109 A074110 A074111 * A074113 A074114 A074115

Keyword

base,nonn

Author

Amarnath Murthy, Aug 27 2002

Extensions

Corrected and extended by Matthew Conroy, Aug 27 2002

Definition corrected by R. J. Mathar, Oct 03 2014

a(8) to a(20) from Charlie Neder, Jan 15 2019

Status

approved