A179522 - OEIS

%I #7 Sep 03 2022 22:43:47

%S 3,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,

%T 103,107,109,127,131,137,151,157,163,167,181,191,193,197,211,227,233,

%U 241,251,257,263,271,277,281,293,307,331,337,367,397,401,409,421,431

%N Prime numbers (A000040) which are also primes in carryless digital root arithmetic in base 10 (A169911).

%C Primes {2,5,7} are units in carryless digital root arithmetic in base 10.

%C 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, ...}.

%C 1 is a unit and also a unit in carryless digital root arithmetic in base 10.

%C What is the asymptotic density of this sequence?

%H <a href="/index/Ca#CARRYLESS">Index entries for sequences related to carryless arithmetic</a>

%F A000040 INTERSECTION A169911.

%Y Cf. A000040, A169911.

%K base,easy,nonn

%O 1,1

%A _Jonathan Vos Post_, Jul 17 2010