|
|
A198805
|
|
Number of closed paths of length n whose steps are 15th roots of unity, U_15(n).
|
|
1
|
|
|
1, 0, 0, 30, 0, 360, 7650, 0, 302400, 4544400, 11226600, 324324000, 4310633250, 24324300000, 437404968000, 5634178329780, 45972927000000, 697866761592000, 8962716395833200, 88725951057744000, 1258898645656852200
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,4
|
|
COMMENTS
|
U_15(n), (comment in article): For each m >= 1, the sequence (U_m(N)), N >= 0 is P-recursive but is not algebraic when m > 2.
|
|
LINKS
|
Table of n, a(n) for n=0..20.
Gilbert Labelle and Annie Lacasse, Closed paths whose steps are roots of unity, in FPSAC 2011, Reykjav´k, Iceland DMTCS proc. AO, 2011, 599-610.
|
|
CROSSREFS
|
Cf. A198808, A321418.
Sequence in context: A023926 A022068 A277043 * A030128 A137348 A137737
Adjacent sequences: A198802 A198803 A198804 * A198806 A198807 A198808
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Simon Plouffe, Oct 30 2011
|
|
STATUS
|
approved
|
|
|
|