%I #4 Mar 30 2012 16:51:46

%S 0,0,28,44,168,612,2520,10356,44712,195120,868224,3905388,17756424,

%T 81376140,375603480,1743843924,8138028696,38146891320,179515196280,

%U 847710124128,4015470916296,19073484584388,90826125756552,433488317523588,2073205037124648

%N Number of n-digit primes in carryless arithmetic mod 10.

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

%F For formula see Maple code.

%p with(numtheory); f:=proc(n) local t1,d; if n <= 1 then RETURN(0); fi; t1:=0; for d from 1 to n-1 do if n-1 mod d = 0 then t1:=t1+(4/(n-1))*mobius((n-1)/d)*(2^d+5^d); fi; od: t1; end;

%Y See A169887 for the actual primes.

%K nonn,base

%O 0,3

%A _N. J. A. Sloane_, Aug 07 2010