editing

approved

A211932 := proc(n)

local a, m;

a := 0 ;

for m from 1 to n do

if gcd(m, n) > 1 then

a := a+numtheory[tau](m) ;

end if;

end do:

a ;

end proc: # R. J. Mathar, Aug 08 2012

Cf.. A143615.

approved

editing

proposed

approved

editing

proposed

A006218a(n)= A143615) = A006218(n)+ A211932) - A143615(n).

A006218(n)= A143615(n)+ A211932(n).

allocated for Naohiro Nomoto

a(n) = Sum_{ m=1..n and gcd(n,m)>1 } tau(m), tau(m)=A000005(m).

0, 2, 2, 5, 2, 11, 2, 13, 9, 19, 2, 28, 2, 29, 25, 32, 2, 47, 2, 50, 35, 50, 2, 69, 19, 62, 41, 72, 2, 96, 2, 80, 59, 86, 47, 114, 2, 99, 72, 118, 2, 144, 2, 125, 107, 125, 2, 164, 31, 158, 100, 151, 2, 188, 71, 174, 112, 167, 2, 229, 2, 183, 151, 188, 87, 247, 2, 208, 142, 252, 2, 271, 2, 228, 203, 238, 85

1,2

Cf.A143615.

allocated

nonn,easy

Naohiro Nomoto, Aug 05 2012

approved

editing

allocated for Naohiro Nomoto

recycled

allocated

editing

approved

Number of distinct finite languages over a unary alphabet, whose minimum regular expression has alphabetic width n.

2, 2, 4, 8, 16, 32, 64

0,1

Hermann Gruber, Jonathan Lee and Jeffrey Shallit: <a href="http://arxiv.org/abs/1204.4982">Enumerating regular expressions and their languages</a>, arXiv:1204.4982v1 [cs.FL]

Cf. A211931.

nonn,more

recycled

Hermann Gruber, May 09 2012

Joerg Arndt: Information now in A000079, see there.