|
|
A300397
|
|
a(n) = number of primes that end in 1 among the first 10^n primes.
|
|
3
|
|
|
1, 24, 245, 2484, 24967, 249934, 2499755, 24999435, 249997579, 2499995131, 24999983109, 249999976990
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
a(1) = 1 because the first 10 primes are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, among which there is only one prime ending in 1.
|
|
PROG
|
(PARI) a(n) = #select(x->((x % 10) == 1), primes(10^n)); \\ Michel Marcus, Mar 07 2018
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base,more
|
|
AUTHOR
|
|
|
EXTENSIONS
|
a(3)-a(8) from Chuck Gaydos
|
|
STATUS
|
approved
|
|
|
|