A300397 a(n) = number of primes that end in 1 among the first 10^n primes.

1, 24, 245, 2484, 24967, 249934, 2499755, 24999435, 249997579, 2499995131, 24999983109, 249999976990

Offset

1,2

Links

Table of n, a(n) for n=1..12.

Formula

a(n) = A185705(A006988(n)). - Michel Marcus, Mar 20 2018

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

Cf. A006988, A030430, A185705, A300398, A300399, A300400.

Sequence in context: A086603 A304835 A281076 * A211148 A296648 A265858

Adjacent sequences: A300394 A300395 A300396 * A300398 A300399 A300400

Keyword

nonn,base,more

Author

G. L. Honaker, Jr., Mar 05 2018

Extensions

a(3)-a(8) from Chuck Gaydos

a(9) from Jon E. Schoenfield, Mar 20 2018

a(10)-a(12) from Giovanni Resta, Mar 27 2018

Status

approved