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A289273
Complement of A242410.
1
4, 25, 26, 27, 28, 30, 32, 35, 36, 39, 40, 55, 56, 65, 66, 69, 70, 72, 74, 75, 76, 78, 80, 95, 96, 105, 106, 108, 110, 114, 116, 121, 122, 123, 124, 126, 128, 132, 134, 135, 136, 140, 141, 143, 144, 145, 146, 147, 148, 153, 154, 155, 156, 161, 162, 165, 166
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
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
Cf. A242410.
Sequence in context: A302624 A238515 A043067 * A309056 A095970 A297963
KEYWORD
nonn
AUTHOR
J. Lowell, Jun 30 2017
STATUS
approved