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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
OFFSET
1,2
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
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