A244265 Frequency of the most common final digit of a prime < 10^n.

1, 7, 46, 310, 2411, 19665, 166230, 1440495, 12712499, 113765625, 1029518337, 9401997000, 86516427946, 801235615814

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Example

Of the primes < 10^2, there are 7 that end in a 3. Since 3 is the most common digit to end with (see A244191), then a(2) = 7.

Prog

(Python)
import sympy
from sympy import isprime
def prend1(d, n):
  lst = [ ]
  for k in range(10**n):
    if isprime(k):
      lst.append((k%10**d))
  new = 0
  newlst = [ ]
  for i in range(10**(d-1), 10**d):
    new = lst.count(i)
    newlst.append(new)
  return max(newlst)
n = 2
while n < 10:
  print(prend1(1, n), end=', ')
  n += 1

Crossrefs

Cf. A244191.

Sequence in context: A190972 A254601 A258340 * A240722 A365773 A067318

Adjacent sequences: A244262 A244263 A244264 * A244266 A244267 A244268

Keyword

nonn,base,hard,more,changed

Author

Derek Orr, Jun 24 2014

Extensions

a(8)-a(14) from Hiroaki Yamanouchi, Jul 11 2014

Status

approved