|
|
A261210
|
|
a(n) = gpf(1 + Product_{k=0..4} prime(n+k)), where gpf is greatest prime factor and prime(i) is the i-th prime.
|
|
1
|
|
|
2311, 1877, 163, 80831, 12647, 6967, 139, 3633983, 1657, 15473, 2970049, 933853, 64776587, 99767, 21067, 84961, 1524137, 820319, 157229, 489427, 2066140207, 71899, 15287, 1680583, 769117, 55732973, 52889, 225941, 4678959379, 1491686591, 87701
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
Array[FactorInteger[1 + Product[Prime[# + k], {k, 0, 4}]][[-1, 1]] &, {31}] (* Michael De Vlieger, Aug 19 2015 *)
|
|
PROG
|
(PARI) gpf(n)=vecmax(factor(n)[, 1]);
first(m)=vector(m, i, gpf(1+prod(j=0, 4, prime(i+j))));
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|