A184272 Number of distinct n X n toroidal 0..3 arrays.

4, 76, 29184, 268447936, 45035996274688, 131176846752109387776, 6467605103205252048452583424, 5316911983139663492479919370381869056, 72172920362019897195243695442781187577923764224, 16069380442589902755419620923449655543228876820136712994816

Offset

1,1

Links

Andrew Howroyd, Table of n, a(n) for n = 1..25

Mathematica

T[n_, k_] := (1/(n*k))*Sum[Sum[EulerPhi[c]*EulerPhi[d]*4^(n*k/LCM[c, d]), {d, Divisors[k]}], {c, Divisors[n]}]; a[n_] := T[n, n]; Array[a, 10] (* Jean-François Alcover, Oct 31 2017, after Andrew Howroyd *)

Crossrefs

Diagonal of A184277.

Sequence in context: A325214 A118193 A052271 * A080989 A006267 A273952

Adjacent sequences: A184269 A184270 A184271 * A184273 A184274 A184275

Keyword

nonn

Author

R. H. Hardin, Jan 10 2011

Extensions

Terms a(6) and beyond from Andrew Howroyd, Sep 27 2017

Status

approved