A053095 Number of primes having exactly the same digits as appear in first n primes.

1, 1, 1, 8, 62, 568, 5370, 114546, 2898058, 0

Offset

1,4

Comments

a(n) = 0 if sum of digits is a multiple of three (see A103208). - Ray Chandler, Apr 07 2010

Links

Table of n, a(n) for n=1..10.

Example

a(4)=8 because the first three prime n, concatenated, are 2+3+5+7 or 2357. There are 8 prime arrangements: 2357 2753 3257 3527 5237 5273 7253 7523.

Prog

(Python)
from sympy import isprime, prime
from sympy.utilities.iterables import multiset_permutations
def A053095(n):
    return sum(1 for d in multiset_permutations(''.join(str(prime(m+1)) for m in range(n))) if isprime(int(''.join(d)))) # Chai Wah Wu, Mar 17 2019

Crossrefs

Cf. A054260, A053160, A053161, A103208.

Sequence in context: A287815 A244831 A331235 * A356461 A099335 A377349

Adjacent sequences: A053092 A053093 A053094 * A053096 A053097 A053098

Keyword

base,nonn,more

Author

Enoch Haga, Mar 19 2000

Extensions

a(7)-a(9) from Ray Chandler, Apr 07 2010

a(10) from Ray Chandler, Apr 08 2010

Status

approved