|
|
A089281
|
|
Smallest prime factor of floor(Pi*10^n).
|
|
5
|
|
|
3, 31, 2, 3, 5, 314159, 2, 2, 3, 3, 5, 2, 13, 163, 43, 13, 2, 317213509, 2, 2, 2, 2, 2, 2, 83, 41, 2, 3, 2, 3, 3, 5, 2, 2, 2, 2, 2, 31415926535897932384626433832795028841, 13, 59, 3, 2, 3, 3, 3, 3, 3, 31, 3, 1657, 2, 3, 2, 2, 2, 29, 13, 2, 3, 2
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
n = 10: floor(Pi*10^10) = 31415926535 = 5*7*31*28954771: a(10) = 5.
|
|
MATHEMATICA
|
a[n_] := FactorInteger[IntegerPart[Pi*10^n]][[1, 1]];
|
|
PROG
|
(PARI) a(n) = factor(floor(Pi*10^n))[1, 1]; \\ Michel Marcus, Dec 28 2013
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|