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A244253 a(n) = the frequency of the most common final digit of a prime with n digits. 0
1, 6, 40, 268, 2103, 17623, 146590, 1274284, 11272025, 101053126, 915755611, 8372478663, 77114448042, 714719245204 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For the most common final digit, see A244189.

LINKS

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

EXAMPLE

Of the 3-digit primes, there are 35 that end in 1, 35 that end in 3, 40 that end in 7, and 33 that end in 9. Thus since 7 has the most, a(3) = 40.

PROG

(Python)

import sympy

from sympy import isprime

def end1(d, n):

..lst = []

..for k in range(10**(d-1), 10**d):

....num = ''

....count = 0

....for i in range(10**(n-d-1), 10**(n-d)):

......if isprime(int(str(i)+str(k))):

........count += 1

....lst.append(count)

..return max(lst)

n = 2

while n < 10:

..print(end1(1, n), end=', ')

..n += 1

CROSSREFS

Cf. A244189.

Sequence in context: A135032 A122074 A289208 * A123357 A081016 A083426

Adjacent sequences:  A244250 A244251 A244252 * A244254 A244255 A244256

KEYWORD

nonn,base,more,hard

AUTHOR

Derek Orr, Jun 24 2014

EXTENSIONS

a(8)-a(14) from Hiroaki Yamanouchi, Jul 10 2014

STATUS

approved

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Last modified October 19 16:17 EDT 2019. Contains 328223 sequences. (Running on oeis4.)