A244265 - OEIS

%I #27 Jul 08 2026 21:49:49

%S 1,7,46,310,2411,19665,166230,1440495,12712499,113765625,1029518337,

%T 9401997000,86516427946,801235615814,7461142986919,69809586085287,

%U 655889293244254,6184988574866752,58514416858480424

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

%e 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.

%o (Python)

%o import sympy

%o from sympy import isprime

%o def prend1(d, n):

%o   lst = [ ]

%o   for k in range(10**n):

%o     if isprime(k):

%o       lst.append((k%10**d))

%o   new = 0

%o   newlst = [ ]

%o   for i in range(10**(d-1), 10**d):

%o     new = lst.count(i)

%o     newlst.append(new)

%o   return max(newlst)

%o n = 2

%o while n < 10:

%o   print(prend1(1, n), end=', ')

%o   n += 1

%Y Cf. A244191.

%K nonn,base,hard,more

%O 1,2

%A _Derek Orr_, Jun 24 2014

%E a(8)-a(14) from _Hiroaki Yamanouchi_, Jul 11 2014

%E a(15)-a(19) from _Benjamin Chaffin_, Jun 07 2026

%E a(19) corrected by _Benjamin Chaffin_, Jul 08 2026