A300398 a(n) = number of primes that end in 3 among the first 10^n primes.

3, 26, 253, 2515, 25007, 250110, 2500209, 25000135, 250002220, 2500000243, 25000027724, 250000009260

Offset

1,1

Links

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

Caldwell and Honaker, Prime Curios!

Formula

a(n) = A185712(A006988(n)). - Michel Marcus, Mar 20 2018

Example

a(1) = 3 because the first 10 primes are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, among which there are three primes ending in 3.

Prog

(PARI) a(n) = #select(x->((x % 10) == 3), primes(10^n)); \\ Michel Marcus, Mar 07 2018

Crossrefs

Cf. A006988, A030431, A185712, A300397, A300399, A300400.

Sequence in context: A067858 A052141 A062793 * A048861 A053972 A204561

Adjacent sequences: A300395 A300396 A300397 * A300399 A300400 A300401

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