OFFSET
1,1
COMMENTS
Conjecture: there will never be a point where this sequence has more terms than A242410. (80 is only the 21st term of this sequence.)
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
A242410:= proc(n) option remember; local Q, k;
Q:= map(procname, numtheory:-divisors(n) minus {1, n});
for k from procname(n-1) + 1 do
if andmap(t -> (k mod t > 0), Q) then return k fi
od
end proc:
A242410(1):= 1:
sort(convert({$1..A242410(1000)} minus map(A242410, {$1..1000}), list)); # Robert Israel, Jul 05 2017
MATHEMATICA
a = {1}; Do[k = a[[n - 1]] + 1; While[AnyTrue[Most@ Rest@ Divisors@ n, Divisible[k, a[[#]] ] &], k++]; AppendTo[a, k], {n, 2, 110}]; Complement[Range@ Max@ a, a] (* Michael De Vlieger, Jul 05 2017 *)
PROG
(PARI) okd(k, vd) = {for (i=1, #vd, if ((k % vd[i]) == 0, return (0)); ); return (1); }
fnext(n, va) = {d = divisors(n); vd = vector(#d-2, i, va[d[i+1]]); k = va[n-1]+1; while (! okd(k, vd), k++); k; }
lista(nn) = {va = vector(nn); va[1] = 1; for (n=2, nn, va[n] = fnext(n, va); ); va; }
CROSSREFS
KEYWORD
nonn
AUTHOR
J. Lowell, Jun 30 2017
STATUS
approved