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
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
KEYWORD
nonn,base
AUTHOR
Lekraj Beedassy, Nov 02 2010
EXTENSIONS
More terms from Robert G. Wilson v, Nov 06 2010
STATUS
approved