login
A179522
Prime numbers (A000040) which are also primes in carryless digital root arithmetic in base 10 (A169911).
0
3, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 127, 131, 137, 151, 157, 163, 167, 181, 191, 193, 197, 211, 227, 233, 241, 251, 257, 263, 271, 277, 281, 293, 307, 331, 337, 367, 397, 401, 409, 421, 431
OFFSET
1,1
COMMENTS
Primes {2,5,7} are units in carryless digital root arithmetic in base 10.
Composites which are also primes in carryless digital root arithmetic in base 10 begin {6, 10, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 27, 28, ...}.
1 is a unit and also a unit in carryless digital root arithmetic in base 10.
What is the asymptotic density of this sequence?
FORMULA
A000040 INTERSECTION A169911.
CROSSREFS
Sequence in context: A031449 A305859 A090260 * A020635 A175820 A127209
KEYWORD
base,easy,nonn
AUTHOR
Jonathan Vos Post, Jul 17 2010
STATUS
approved