A181576 Primes whose factorials end with a prime number of trailing 0's.

11, 13, 17, 19, 31, 59, 83, 127, 151, 173, 179, 197, 199, 223, 293, 367, 397, 421, 439, 449, 461, 463, 557, 569, 607, 617, 619, 631, 659, 733, 773, 797, 853, 919, 941, 967, 1013, 1039, 1061, 1063, 1087, 1097, 1123, 1181, 1259, 1399, 1423, 1447, 1543, 1567

Offset

1,1

Comments

For the corresponding prime number of trailing end 0's, see A181577.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

A027868(a(n)) = A181577(n). - Amiram Eldar, May 03 2024

Example

The factorial 2! = 2 ends with 0 zeros, so the prime 2 is not in the sequence because 0 is not a prime.
The factorial 5! = 120 ends with 1 zero, so the prime 5 is not in the sequence because 1 is not a prime.
The factorial 11! = 39916800 ends with 2 zeros, so the prime 11 is in the sequence because 2 is a prime.

Mathematica

Select[ Prime@ Range@ 250, PrimeQ@ IntegerExponent[ #! ] &] (* Robert G. Wilson v, Nov 06 2010 *)

Prog

(PARI) is(p) = isprime(p) && isprime((p - sumdigits(p, 5))/4); \\ Amiram Eldar, May 03 2024

Crossrefs

Cf. A027868, A039716, A181577.

Sequence in context: A208270 A106101 A032590 * A076162 A156902 A050674

Adjacent sequences: A181573 A181574 A181575 * A181577 A181578 A181579

Keyword

nonn,base,changed

Author

Lekraj Beedassy, Nov 02 2010

Extensions

More terms from Robert G. Wilson v, Nov 06 2010

Status

approved