OFFSET
1,1
COMMENTS
a(16) > 10^13. - Giovanni Resta, Jul 25 2013
The convention gpf(1) = A006530(1) = 1 is used (otherwise we would have a(2) = 2 and a(3) = 24). - Pontus von Brömssen, Dec 05 2022
a(17) > 10^14. - Martin Ehrenstein, Dec 10 2022
FORMULA
EXAMPLE
a(7) = 9352 because the first sequence of seven consecutive numbers with increasing greatest prime factors is 9352=167*7*2^3, 9353=199*47, 9354=1559*3*2, 9355=1871*5, 9356=2339*2^2, 9357=3119*3, and 9358=4679*2. [Corrected by Jon E. Schoenfield, Sep 21 2022]
MAPLE
V:= Vector(11): count:= 0:
a:= 1: m:= 1: w:= 1:
for k from 2 while count < 11 do
v:= max(numtheory:-factorset(k));
if v > m then m:= v
else
if V[k-a] = 0 then V[k-a]:= a; count:= count+1; fi;
a:= k; m:= v;
fi
od:
convert(V, list); # Robert Israel, Dec 05 2022
PROG
(Python)
from sympy import factorint
def A358890(n):
m = 1
gpf1 = 1
k = 1
while 1:
while 1:
gpf2 = max(factorint(m+k))
if gpf2 < gpf1: break
gpf1 = gpf2
k += 1
if k == n: return m
m += k
gpf1 = gpf2
k = 1 # Pontus von Brömssen, Dec 05 2022
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Reinhard Zumkeller, Jan 10 2003
EXTENSIONS
More terms from Don Reble, Jan 17 2003
Corrected by Jud McCranie, Feb 11 2003
a(14)-a(15) from Giovanni Resta, Jul 25 2013
Name edited, a(1) and a(2) corrected by Pontus von Brömssen, Dec 05 2022
a(16) from Martin Ehrenstein, Dec 07 2022
STATUS
approved