The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A256039 Triangle read by rows: number of idempotents of rank k in partial Brauer monoid PB_n. 0
 1, 1, 1, 4, 2, 1, 16, 18, 3, 1, 100, 88, 48, 4, 1, 676, 860, 280, 100, 5, 1, 5776, 6696, 4020, 680, 180, 6, 1, 53824, 76552, 35196, 13580, 1400, 294, 7, 1, 583696, 805568, 531328, 131936, 37240, 2576, 448, 8, 1, 6864400, 10765008, 6159168, 2571744, 397656, 88200, 4368, 648, 9, 1, 90174016, 141145120, 101644560, 32404800, 9780960, 1027152, 187320, 6960, 900, 10, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS Table of n, a(n) for n=0..65. I. Dolinka, J. East, A. Evangelou, D. FitzGerald, N. Ham, et al., Enumeration of idempotents in diagram semigroups and algebras, arXiv preprint arXiv:1408.2021 [math.GR], 2014. EXAMPLE Triangle begins: 1, 1, 1, 4, 2, 1, 16, 18, 3, 1, 100, 88, 48, 4, 1, 676, 860, 280, 100, 5, 1, 5776, 6696, 4020, 680, 180, 6, 1, 53824, 76552, 35196, 13580, 1400, 294, 7, 1, 583696, 805568, 531328, 131936, 37240, 2576, 448, 8, 1, 6864400, 10765008, 6159168, 2571744, 397656, 88200, 4368, 648, 9, 1, 90174016, 141145120, 101644560, 32404800, 9780960, 1027152, 187320, 6960, 900, 10, 1, ... CROSSREFS Sequence in context: A236830 A269736 A264535 * A152391 A144088 A039948 Adjacent sequences: A256036 A256037 A256038 * A256040 A256041 A256042 KEYWORD nonn,tabl AUTHOR N. J. A. Sloane, Mar 14 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified March 1 06:15 EST 2024. Contains 370430 sequences. (Running on oeis4.)