A198803 Number of closed paths of length 17n whose steps are 17th roots of unity.

1, 355687428096000, 2252447502438386084347676160000000, 91637618063484032681381970173925718228992000000000000, 8528384964488882787308232082310780143738202829970606470279000000000000000

Offset

0,2

Comments

Equivalently, the number of paths of length 17n in Z^17 from {0}^17 to {n}^17. - Andrew Howroyd, Nov 01 2018

Links

Andrew Howroyd, Table of n, a(n) for n = 0..40

Gilbert Labelle and Annie Lacasse, Closed paths whose steps are roots of unity, in FPSAC 2011, Reykjavik, Iceland DMTCS proc. AO, 2011, 599-610.

Formula

a(n) = (17*n)!/(n!)^17. - Andrew Howroyd, Nov 01 2018

Prog

(PARI) a(n) = (17*n)!/(n!)^17; \\ Andrew Howroyd, Nov 01 2018

Crossrefs

Row n=17 of A187783, column k=17 of A089759.

Sequence in context: A239922 A011528 A172542 * A317290 A128769 A261150

Adjacent sequences: A198800 A198801 A198802 * A198804 A198805 A198806

Keyword

nonn

Author

Simon Plouffe, Oct 30 2011

Extensions

Sequence redefined and a(2)-a(4) from Andrew Howroyd, Nov 01 2018

Status

approved