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

1, 355687428096000, 2252447502438386084347676160000000, 91637618063484032681381970173925718228992000000000000, 8528384964488882787308232082310780143738202829970606470279000000000000000

Offset: 0

Author

Simon Plouffe, Oct 30 2011

Keywords

• nonn

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.

Crossrefs

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

Programs

PARI

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

Formula

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

Extensions

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