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

0,3

Links

Table of n, a(n) for n=0..24.

Index entries for sequences related to carryless arithmetic

Formula

For formula see Maple code.

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;

Crossrefs

See A169887 for the actual primes.

Sequence in context: A326234 A260954 A349495 * A219685 A180045 A144581

Adjacent sequences: A169959 A169960 A169961 * A169963 A169964 A169965

Keyword

nonn,base

Author

N. J. A. Sloane, Aug 07 2010

Status

approved