|
|
A368261
|
|
Table read by antidiagonals downward: T(n,k) is the number of tilings of the n X k cylinder up to vertical reflection by an asymmetric tile.
|
|
2
|
|
|
1, 3, 2, 4, 7, 2, 10, 20, 14, 4, 16, 76, 88, 40, 4, 36, 272, 700, 532, 108, 8, 64, 1072, 5472, 8296, 3280, 362, 10, 136, 4160, 43800, 131344, 104968, 21944, 1182, 20, 256, 16576, 349568, 2098720, 3355456, 1399176, 149800, 4150, 30
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
EXAMPLE
|
Table begins:
n\k| 1 2 3 4 5 6
---+----------------------------------------
1 | 1 3 4 10 16 36
2 | 2 7 20 76 272 1072
3 | 2 14 88 700 5472 43800
4 | 4 40 532 8296 131344 2098720
5 | 4 108 3280 104968 3355456 107377488
6 | 8 362 21944 1399176 89484128 5726689312
|
|
MATHEMATICA
|
A368261[n_, m_]:=1/(2n)*(DivisorSum[n, EulerPhi[#]*2^(n*m/#)&] + If[EvenQ[m], DivisorSum[n, EulerPhi[#]*2^(n*m/LCM[#, 2])&], DivisorSum[n, EulerPhi[#]*2^(n*m/#)&, EvenQ]])
|
|
CROSSREFS
|
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|