A169962 Number of n-digit primes in carryless arithmetic mod 10.

0, 0, 28, 44, 168, 612, 2520, 10356, 44712, 195120, 868224, 3905388, 17756424, 81376140, 375603480, 1743843924, 8138028696, 38146891320, 179515196280, 847710124128, 4015470916296, 19073484584388, 90826125756552, 433488317523588, 2073205037124648

Offset: 0

Author

N. J. A. Sloane, Aug 07 2010

Keywords

• nonn
• base

Links

• Index entries for sequences related to carryless arithmetic

Crossrefs

See A169887 for the actual primes.

Programs

Maple

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;

Formula

For formula see Maple code.